GREEN DATA CENTER COOLING

Transcription

1 GREEN DATA CENTER COOLING We design cooling solutions for future datacenters using renewable solar energy while reducing electricity consumption cost. Kristian Fredslund, Fridrik Rafn Isleifsson, Julie Juel Andersen, Martina Zamboni, and Oxana Pantchenko 8/19/2009

2 GREEN DATA CENTER COOLING We design cooling solutions for future datacenters using renewable solar energy while reducing electricity consumption cost. ABSTRACT This report presents a business plan for a company that sells cooling solutions for data centers. The main objective is to reduce electrical consumption using solar powered absorption cooling. There is an increasing demand for data centers and therefore an increased electricity demand. In 2006, this particular sector acquired 61 billion kwh of electrical energy, which is approximately 1.5 percent of total electricity consumption in the United States. Future predictions state, that by the year of 2011, the energy consumption will exceed 100 billion kwh, for a price of 7.4 billion USD. In an average data center, 30-40% of the electricity is consumed by the cooling system. The aim of this study is to show whether a particular cooling system, can reduce the electricity costs, CO2 emissions and if it is profitable to base a business on. The outcome shows the cost of the absorption chiller and the solar collectors is close to twenty five times the cost of a conventional chiller, but with the reduced power consumption the cost is earned back in savings on energy purchase. Assuming a power consumption of 70 kw for a conventional chiller, the annual power consumption is 613,200 kwh. The total cost is 91,980 USD per year for the cooling of the data center only. Calculating the break-even point for the cooling system, it can be seen that in 6,7 years the absorption chiller has cost the same as the initial and running costs of a conventional cooling system. 1

3 Contents Abstract... 1 Introduction... 3 Background... 3 Data Center and Its Energy Use... 5 Business Proposal... 7 Business Model and Pricing... 9 Sales and marketing Solar Powered Data Center Cooling Competing Technologies Slide The Team Conclusion Who did what References Appendix A Field Trip Diaries

4 INTRODUCTION Background In the past few years, the renewable energy sources topic has been a frequent discussion leader among politicians, economists and scientists. The demands of energy are growing continuous as many professionals with different backgrounds focus on the same problem of shortage of energy. For the past several decades, government, academic, telecommunications and business sectors have been slowly digitizing their daily activities and processes[1]. With that thought, demand for data centers has been rising in every sector of economy. Currently, there are several factors that increase demand for data centers. They include; The increase use of electronic transactions in financial services The growing use of internet communication and entertainment The shift to electronic medical records for healthcare The growth in global commerce and services The adoption of satellite navigation High performance scientific computing [1] Sequentially, the number of data centers increased significantly in the last several years causing to increasing energy consumption for its purposes. Between the year of 2000 and 2006, the energy consumption doubled. In 2006, this particular sector acquired 61 billion kwh of electric energy, which is approximately 1.5 percent of total electricity consumption in the United States. The cost of this amount of energy approximates into 4.5 billion United States dollars[1]. Figure 1 demonstrates number of data centers in the United States between years of 2000 and

5 Figure 1. Number of Data Centers in US. Localized Data Center was assumed to be less than 1000 sq. ft. with 100 servers, Mid-tier Data Center was assumed to be less than 5000 sq. ft. with 240 servers and Enterprise-Class Data Center was considered to be over 5000 sq. ft. holding approximately 500 servers. When considering current efficiency trends and national energy consumption up to date, by the year of 2011, the energy consumption should be more than 100 billion kwh, for a price of 7.4 billion United States dollars. In order to accommodate such load on the power grid, additional 10 new power plants would have to constructed and operate at a full capacity[1]. 4

6 Data Center and Its Energy Use Data center is a centralized repository used for storage, management and dissemination of data and information organized around a particular body of knowledge or pertaining to a particular business. A data center contains equipment used for data processing, data storage and communications[2]. In many cases, data centers also have special power conversion units and backup equipment to maintain the proper temperature and humidity inside a data center. It has been known that data centers can draw as much as 40 times electrical energy as conventional office buildings[1]. Typically, data centers have no windows and very little circulation of fresh air. They are designed to hold maximum number of computer at maximum operation. The size of a typical data center varies from small room to large building, also known as enterprise class data centers[1]. Data centers can easily recognize by equipment racks that contain servers, storage devices and network equipment. Before each rack, electricity is first supplied to an uninterruptible power supply (UPS) unit. It acts as a battery backup to prevent business disruption or data loss[1]. Figure 2 demonstrates major electrical components of a data center. Figure 2 Typical Electrical Components in a Data Center[1] 5

7 Since data centers operate 24 hours a day and 365 days a year, servers and power delivery equipment generate significant amount of heat. In order for this equipment to function properly, this heat has to be removed from the data center. In many cases, such heat in data centers can be removed by computer room air conditioning units[1]. Such units contain fans, filters, cooling coils, and other equipment that conditions and distributes air throughout the data center room. Many data center rooms are designed in such a way that only small amount of air enters from outside. Three main components that consume the most power are servers, cooling equipment and power delivery[1]. Only half of the power that enters the data center is used for servers the other fifty percent is divided between powering cooling and power equipment[1]. Figure 3 demonstrates total electricity use for server in the US and the world in 2000 and 2005, including associated cooling and auxiliary equipment. Figure 3 Total electricity use for servers in the US and the world in 2000 and 2005, including the associated cooling and auxiliary equipment. [3] 6

8 BUSINESS PROPOSAL The Problem and Value Proposition THE PROBLEM AND VALUE PROPOSITION "Our new data center uses half of the energy of the total office building." "Electricity used in data centers are expected to rise to 5% of total use in US" "Researchers are already discarding projects because we cannot supply the computing power they need." Cost per 16 years in US dollars Reference System Proposed System UPS investment UPS running battery cost Chiller investment Chiller power consumption Backup generator Total Figure 4 The Problem and Value Proposition The slide above shows a comparison of initial and operating costs between a reference data center and a data center of the same capacity using the proposed cooling technique. To estimate the economical feasibility of using absorption cooling instead of conventional cooling systems, a comparison of initial cost and operating costs over a time period is made. Doing this it is possible to find out how long it takes for the absorption cooling system to earn its initial cost back in saved energy consumption. About 30-40% of the electricity consumption in an average data center goes to the cooling system, this part of the electrical consumption can be removed using solar powered absorption cooling. It is also possible to reduce initial 7

9 costs of UPS and backup generators, because the absorption cooling system does not need an electricity supply to function. In a reference system that has a total power consumption of 200 kw, it can be assumed that approximately 50 % goes to the servers, 15 % to other use and 35 % is used by the cooling system. As the absorption cooling does not need UPS or backup power the power output of the UPS and the backup generators can be reduced by 35 %, reducing the initial investment of the data center. The cost of the absorption chiller and the solar collectors is close to ten times the cost of a conventional chiller, but with the reduced power consumption the cost is earned back in savings on energy purchase. The initial investments are UPS s, backup generator and chillers. The UPS s cost 100, USD for each 100 kw [4], a 150 kw gas powered generator costs 24,000 USD [5]. The chillers cost 32,000 USD for a conventional chiller and 790,000 USD for a solar powered absorption chiller, where 132,000 USD is the cost of the solar collectors and 588,000 USD is the cost of the absorption chiller and 69,000 USD is the cost of ice storage.[6]. Assuming a power consumption of 70 kw for a conventional chiller, the annual power consumption is 613,200 kwh. Today, the average price of one kilowatt hour is 0.17 USD for the summer and 0.13 USD for the winter period, giving a total cost of 91,980 USD per year only for the cooling of the data center [7]. Now it is possible to calculate the simple break-even point for the cooling system, using the above costs for initial and running costs it can be seen that in 6.7 years the absorption chiller has cost the same as the initial and running costs of a conventional cooling system. 8

10 BUSINESS MODEL AND PRICING BUSINESS MODEL AND PRICING Chiller package o Using of the shelf components o Absorption technology and solar collectors o Eliminate cooling electricity load Eliminate traditional chillers in new data centers Price basis: o Chiller: $147k o Chiller installation: $50k o Solar collectors: $132k (including installation) o Profit margin: $50k (15%) Selling price: $380k Comparable std. installations: $73k Component producer System designer System Implement or Operator/m aintenence End User Figure 5 Business Model and Pricing Figure 5 describes the business model of this company, basically how we are going to make money. We have done cost calculations so we can estimate the savings to a costumer and figure out the best marketing strategy. The main issue here is that the capital costs are almost an order of magnitude larger than for the conventional system. But the energy efficiency will cover this expense quickly. See Appendix A for further calculations and investigations. Another issue is the overall company strategy. After the first pilot plant is built, how is the company going to make money. Where in the value chain can the company contribute the most to the overall value. This issue has not been solved completely and is one of the things that have to be considered if the business plan is to be implemented. 9

11 SALES AND MARKETING SALES AND MARKETING In 2009, there are approximately 6000 data centers in the US, they use 1,2% of the total electricity, expected to rise to 5% in An estimated 1000 of those are from KW in California. Server lifetime 3 years, installation lifetime 16 years Collective computing power doubles every 18 months 200 New/refurbished data centers in this segment each year Data centers are mostly individually designed by operator in cooperation with independent consultants Number of Data Centers in US Market entrance: o Target consultants promoting green solutions o Build promotion centers (public) to create awareness o Cooling is normally not operated by sysadmins (target might be building operators) Number of Data Centers Localized Data Center Mid-tier Data Center Enterprise-class Data Center Figure 6 Sales and Marketing Figure 6 holds the key information about the market that we are targeting. Extensive research has been carried out to get numbers of data centers and the overall market segmentation. Interviews and field studies have been conducted with representative costumers in the market. The process of how the data center is built and what actors are involved in the design and construction is still not well defined. There are still unknowns concerning the extent at which the different stakeholders can influence a decision concerning the cooling system. The growth in the market is unquestionable, but the introduction of virtual servers can reduce the power consumption and the total computational load in the data centers. This has the present influence that server loads are actually dropping while the number of services is staying the same or increasing[8]. 10

12 Silicon Valley is one of the world s data-center-hotspots, but also located in a climate with higher temperatures and a high solar influx. This makes the location ideal for implementation of solar powered cooling. A large concentration of datacenters with the same regulatory framework and location is a natural first target segment. MARKET DRIVERS Rising energy costs + consumption Make the data center more "green" "LEED" points attainable for cooling solution Incentives for Renewable & Efficiency: (Our package complies with California Energy Code standards (Title 24)) Energy-Efficient Commercial Buildings (Federal) o $1.80 per square foot for buildings that save 50% or more are eligible for a tax deduction o $0.60 per square foot for buildings that save 20% on cooling Buildings must meet the ASHRAE standard. California Solar Initiative (State rebate program) Offers 10 years of State rebates from PG&E, SCE and SDG&E, depending on system size and performance. Non residential customers> 50kW gain USD per Watt Incentives declines in a step based system Figure 7 Market Drivers Figure 7 summarizes the different market drivers towards our solution we have identified in our research. The two main drivers are the ability to reduce electricity cost and to provide a greener solution than today. Other factors that influence the markets decisions are the public funded incentives and LEED certification points. Energy efficiency standards for residential and nonresidential buildings are set by Part 6 of the California Energy Code. These standards, well known as Title 24, were established in 1978 as a response to a legislative mandate to reduce California's energy 11

13 consumptions. Since then, standards have been updated periodically to allow new energy technologies and methods. Projects that apply for a building permit on or after this date must comply with the 2005 Standards, while 2008 standards will be effective from January 1st, There are also appliances efficiency standards for lighting, heating, cooling equipment, water heaters, etc. (Household Appliance Efficiency Regulations, 2007). In addition to this, specific standards for cooling applications are set by ASHRAE (American Society of Heating, Refrigerating and Air-Conditioning Engineers). Federal tax incentives provide a tax deduction of 1.80 USD per improved square foot to owners of new or existing buildings who reduce the building s total heating, cooling, ventilation, water heating and interior lighting energy cost by 50% or more compared to the ASHRAE Standard reference building. Partial deductions of 0.60 USD per square foot are available for owners installing improvements to the building envelope, lighting, or HVAC of a building that reduces either heating, cooling or interior lighting energy by 16%. At state level, California Solar Initiative (CSI) offers 10 years of state solar rebates from PG&E, SCE and SDG&E. Rebates vary according to system size and performance, and decline in time on a step based system. However, the goal of this company is to be able to provide a product that in its own right is so appealing to the costumer that they will buy it. On that basis, no governmental subsidies are included in the economic feasibility studies. Only the simple direct savings are included. 12

14 SOLAR POWERED DATA CENTER COOLING SOLAR POWERED DATA CENTER COOLING 2.5KWh 100KW Data Center Example 1100m 2 solar collectors (a redzone) 2400KWh cooling/sun required, 6 hour sun time 1800KWh storage, 2 tons of ice = 21 m 2 IP could be developed in controls and storage management Well tested and documented technology 100% renewable cooling, providing storage + unlimited runtime* 1KWh light heat 1KWh Adsorp. Chiller Ice Ice storage CW 1KWh Data Center Figure 8 Solar Powered Data Center Cooling Solar cooling (later called SC) is a solar technology that produces cold by exploiting solar energy. A big potential for this technology comes from the fact that, in many cooling applications, the greatest demands occurs when solar radiation is at maximum. However, this is not quite the case for data centers, whose energy requirement is almost constant in time. Please refer to Figure 9. Figure 9 UPS daily consumption, UCSC data center[8]. 13

15 There are two practical approaches to solar cooling: 1. Pair a PV array with a standard air conditioning unit. 2. Pair a solar thermal collector with an absorption chiller. In case 2, the system should be grid-tied so that if the PV system is insufficient or if cooling is not required electricity can be transferred to and from the grid. Photovoltaic refrigeration, although uses standard refrigeration equipment which is an advantage, has low efficiency and higher costs. In fact, the price for solar thermal energy is currently 0.31USD/kWh, while PV is 0.50 USD/kWh. Peak price is 0.5 USD/Wpeak, while PV is still 8 USD/ Wpeak. [9-10]. The PV solution is not cost effective, and will not be discussed here. In the SC system in exam, the heat from the sun is collected and transferred to an adsorption chiller, where ice production happens through a thermodynamic cycle. In order to provide 24 hours of cooling power, ice from the chiller is stored in a tank, and melt later on at night. We use non imaging, stationary solar collector. The specific design is Winston Compound Parabolic Collector (XCPC), a basic stationary parabolic collector coupled to a Dewar type evacuated tube. See Figure 10. The design has been developed by the Argonne National laboratory in the early 70 s, and improved by R. Winston in Figure 10 Cross section profile of a basic stationary XCPC [12] 14

16 The XCPC has a wide acceptance angle (+/-35 ) and can operate without tracking, thus decreasing the cost. As a downside, concentration ratio is only x, depending on incidence angle. Efficiency depends on both optical and thermal properties. See Figure 11. Optical efficiency, (accounting for absorption, reflection and geometry, is η0=0.59. Besides, there are thermal losses due to the difference in temperature between the fluid and the environment. The useful power can be estimated as: Puseful = η0 A*I Ploss (Tcoll, Tamb)*A where A is the collector aperture area, I is incident solar radiation, and Ploss is heat loss per unit area per unit time, which is function of the average collector operating temperature (Tcoll) and average ambient temperature (Tamb). Thermal efficiency would decrease with increasing temperature difference. See Figure 12. Figure 11 Efficiency vs. temperature difference in evacuated solar collectors, at different concentrations. XCPC is assumed to follow the 1.5x curve [12]. All components are low cost, with minimal operation and maintenance and expected lifetime of 15 years. Estimated production and installation cost is 100 USD per square meter [13]. 15

17 Figure 12 Efficiency vs. temperature for XCPC collectors[13]. Collectors are sold in modules consisting of 6 tubes, whose gross dimensions are 1.6 x 1.3 x 0.2 m. Assuming that California receives 6 hours of peak solar irradiance per day [14]. See Figure 13 for typical daily irradiance. Assumed that the efficiency of solar collectors is 0.4 at 180 degrees Celsius (Figure 12), it would require a surface of 1100 square meters (a football field) to cover the energy consumption of a 100kW data center. A fraction of this energy (1800 kwh) would be stored in a 21 m 3 tank, containing 2 tons of ice. Figure 13 Daily solar radiation and rain in San Diego, Ca, on August 18 th, 2009 [15] 16

18 COMPETING TECHNOLOGIES SLIDE COMPETING TECHNOLOGIES 100KW Servers installed Solar area [m2] Grid power use [KW] Capital Cost Running cost Reliabili ty Green image Carbon footprint Conventional chiller 150 Very low Very high Decent Bad High PV panels conventional cooling 1420 Low Low Decent Very good, PV Low Solar concetrated power and UPS 5670 Very high Very low Good Good Low SC powered absorbtion 1420 High Low Good Good, solar Low Figure 14 Competing Technologies The following equation was used to calculate the area of solar panels needed to provide the desired amount of energy. 1 η η Where PCooling is the cooling power needed, ηcooling is the efficiency of the cooling system, ηsolar is the efficiency of the solar panel and A is the area of the solar panels and calculating for 24 hours, using a solar influx of 5.5 kwh/m 2. For a data center with a consumption of 130 kw, using PV panels to supply a conventional cooling system: PCooling = 130 kw, ηcooling = 2, ηsolar = ,

19 For a data center with a consumption of 130 kw, using solar collectors supplying an absorption cooling system: PCooling = 130 kw, ηcooling = 1, ηsolar = , For a data center with a consumption of 130 kw, using solar collectors to supply an absorption cooling system and a stirling engine utilizing heat from the solar collectors to provide power to the data center. PCooling = 130 kw, ηcooling = 1, ηsolar = 0.4, ηstirling , Explanation of the cost, reliability and Carbon footprint. Systems can be stated with a "good" reliability, if they do not rely on electricity from the grid. The grid in US is not always reliable, so with systems that is feed by a renewable source such as solar-energy is more reliable. In our solution of Solar Collectors that powers absorption cooling the reliability can be stated good. Furthermore the case also includes generator and UPS, so the customers, are not to be concerned. A conventional chiller is stated "decent", on reliability, because it relies on the grid. When powers black out, there will be no back ups for running the conventional chillers. Reliability is also measured for the equipment. Addressing the environmental concerns Renewable Cooling products are a step on the way to reduce you Carbon Footprint. 18

20 For addressing the environmental concerns and reduce the Carbon Footprint with Renewable Cooling, you will save both money and Carbon Footprint by skipping electricity from the grid. Furthermore less back up UPS batteries are needed. Result: + Decrease electricity consumption from the grid + Decrease material use and electronic equipments = Less Carbon Footprint. Measuring the Carbon Footprint for all the four different systems requires the program of SimaPro or others. It is doubly a thing to consider, specially the production of lead-acid batteries for the UPS are one of the main culprits. A large Global warming culprit is the production of electricity. The harmful effect varies according how it is produced. If the electricity is produced in Denmark the factor of harmfulness is bigger (factor 0.5) than it is for the electricity produced in California (factor 0.24). The reason is that in California they use far more Renewable Energy than in Denmark. By using the SC powered absorption system instead of a conventional chiller system to cooling of 100 kw Data Center the CO2e emissions will be reduced by: 613,200 kwh / year*0,24 (factor / kg) = 147,168 Kg CO2e per year. 19

21 THE TEAM AND MILESTONES THE TEAM THAT WILL PUSH FORWARD CEO Market Experience Business Strategy Entrepreneurship System Designer Experience Connections System Integrator Technical Experience Operator Technical Experience Figure 15 The Team MILESTONES Pilot ordered 6/10 1st plant operational 12/10 Pilot tests complete 12/11 year 1 year 2 year 3 year 4 year 5 Figure 16 The Milestones 20

22 CONCLUSION The market for data center cooling is a large market with a steady growth. The drivers for adopting new technologies are strong and will most likely intensify in the future. We have a solid technical solution for a problem that is readily identified by the costumers. A cooling solution with an absorption chiller and ice storage is a viable solution for data centers located in sunny areas. The investment costs are high, but the savings in electricity costs are significant. Utilizing the suns energy will enable the cooling to run almost without any use of electricity. This will both improve the costumer s green image as well as the lowering their electricity bill. The main identified problem is the business proposal. How can this company continue to make money after the first pilot plants are built? What is the continuous contribution to the value chain? This will have to be addressed, but can be solved without a doubt so that the business can grow and decrease the overall data center energy use. WHO DID WHAT Kristian did most of the cooling research and calculations. Martina did solar and part of the legislature. Julie did empirical data research and cost and environment impact calculations. Fridrik did energy costs and calculations. Oxana did market size analysis and history related research. The writing of the report was done tight collaboration between every member of the group. 21

23 REFERENCES 1. U.S. Environmental Protection Agency, E.S.P., Public Law : Report to Congress on Server and Data Center Energy Efficiency Public Law US Environmental Protection Agency ENERGY STAR Program. 2007, U.S. Environmental Protection Agency, ENERGY STAR Program 2. TechTarget. SearchDataCenter.com Definitions [cited 2009; Available from: 3. Koomey, J.G., Estimating total power consumption by servers in the US and the world. Final report. February, APC.com, Symmetra PX PoweredGenerators.com. Guardian Elite 150kW 6.8L Generator Review 2009 [cited; Available from: 6. Winston, R., Solar Collectors with Evacuated Receiver and Nonimaging External Reflectors. 2004, Foley and Lardner: US. 7. Company, P.G.E [cited; Available from: 8. UCSC: ITS Data Center Tour, in Eric Keisler. 2009: Santa Cruz, CA. 9. J. Norwood,N. Kamphuis, D. Sotham, MSE 226: Distributed Solar Thermal/Electric generation (2007) 10. A. Nottrott, Solar Radiation In California Report, UC San Diego J. O'Gallagher, Nonimaging Optics in Solar Eergy, Morgan & Claypool Publisher (2008) 13. R. Winston, Solar collectors with evacuated receiver and nonimaging external reflectors, US Patent n.us 2004/ A1 (2004) 14. National Solar Radiation Data Base (NSRDB), UC San Diego Decision Making Using Real-time Observations for Environmental Sustainability (DEMROES),

24 APPENDIX A FIELD TRIP DIARIES Zero Motor Cycles Friday, July 31, 9:30 am - 10:30 am Founded in 2006 with approx $450k angel funding. Neal Sykie, aerospace engineer, educated by calpoly, worked in nasa doing transport analysis. $25m additional funding from private equity fund in NY. Started by 4 rich Belgian families. Initial $25m growth to $4b. strategic investors. None of the ones in Silicon Valley were interested. Break even expected q The key is the batteries, the li-ion technology was the enabling factor that made electric motorcycles feasible. Last year was full blast on production, improvements have been implemented within the year, jumps in performance have been seen. The key performance indicators are $/kwh and energy density within the batteries. Tha battery capacity is 3,8KWh in a package of 85 pounds. The spare part cost of the battery is $5000. A full charge will take 4 hours, but most of the trips will be smaller and the charging time is much less. The deep-cycle recharge will take a heavy toll on battery life. The number of cycles (deep charge) was to be hundreds, but the smaller quick charges is not noticeable on battery performance. The battery is considered dead when the full charge capacity is less than 80% of the beginning value. The continuous current draw is 100 amps and with a voltage of 50V then the running effect is 5kw, but the peak power output goes up to 17kw. 23

25 The company has an mechanical engineering department, working with SolidWorks and finite element model analysis. The design of the motorcycle frame is their own and is tailored specifically for an electric motorcycle. The weight is very low, the frame is only around 30 pounds. They also have an electrical engineering department, working on their own brushless engine design (not implemented). Their main products are a charging device monitoring the individual cells to make sure that the charging and load on each cell is well balanced. They are also moving on a motor controller and have problems getting the skilled engineers that know analog to digital conversions. weight Battery capacity range Top speed 0-30 mph Price Swap battery Dirt bike ,5k No Urban 55 2,5 10k yes 2 main competitors shipping electric motorcycles (larger than scooters): Bravo and Quantia. Today the production facility can produce 10 bikes a day, but at the end of 2010 they expect to ramp up production to 20 bikes /day. The motors used today are brushing motors with no regenerative breaking. The new design will be better motors with engine braking capabilities. They have put a lot of effort into making the throttle response of the motorcycle as close as possible to the dynamics of a traditional ICE motorcycle. The weight of the motorcycle is less than that of conventional ICE motorcycles. The limited amount of power available makes weight hugely important. NASA Ames Friday, July 31, 11am 12pm NASA Ames is placed just before the area of the innovative area of Silicon Valley. Started as NACA in 1939 the area now has employees. Unfortunately, we did not have the time to go inside in the different tunnels and buildings, but we got a guided tour around the buildings. Wind tunnels and Hangar: As we walked around we looked at, and told about, the large hangar that is found inside NASA Ames. It has the space for 3 Titanic. The hangar is the second hangar in the history of NASA. The first was placed in Langley. Facilities at NASA Ames also include wind tunnels as big as 80 * 100 fod. The largest test can be done at miles per hour. Furthermore, a smaller wind tunnel with wind speeds up to miles per hour is part of the facilities of NASA. The Blower in the tunnel has HP made by a power plant. They have a High Voltage directly to the tunnel. 24

26 All simulations are made by super-computers. Actually the world s thirds largest computer is at NASA Ames. NASA Ames Microgrid Facility Testbed Friday, July 31, 11am 12pm UC Santa Cruz had in the lab facilities at NASA Ames installed a 1KW solar array. The array is mounted in a tracking system that improved the performance of the panel. The tracking system has a material cost of approximately $6000, but the real cost is the installation which amounted to $ The tracking system and installation is therefore by far the most expensive part of the system. The tracker operates with at small solar detector at the top of the panel and the panel then turns, (slowly but steadily) towards the one of the diodes that receives the most sunlight. They have installed an expensive measuring device that can make IV-curves for the panel; the device utilizes an capacitor, which gives the ability to provide a full spectrum of load from short circuit to no load. They did two different sweeps to illustrate the difference between a properly tracked panel and a panel facing away from the sun. 25

27 They have not done any lifecycle analysis on the panels, but they expected the power consumption from making the panel would be offset after 1 to 2 years (this should be validated in an analysis). San Luis Reservoir Saturday, August 1, 8am 10am The San Luis reservoir is an artificial lake made as a part of a water distribution system for California and electrical energy storage. To make the reservoir a dam was built in the valley and water was led through channels to fill it up. To store electrical energy water is pumped up to the reservoir and during high demand time is used to produce electrical energy. Using renewable energy sources to pump the water, while demand for electricity is low and energy would otherwise go to waste; this method for storing electrical energy has the potential to increase use of renewable energy sources. The technology used is well known and tested so technological challenges are few, but to make this method for energy storage more attractive the efficiency of the pumping process would need to be improved so as not to waste to big a part of the energy. Because the same machine is used for pumping water and producing electricity a compromise on the type of turbine wheel must be made, the power plant uses Francis turbines which are not the most efficient types of turbines for pumping and generating for this particular site, but are the best option while combining the two processes. For building more hydro storage plants the biggest obstacle would be getting it approved due to environmental concerns. The reservoir can change the height of ground water in the immediate area, turning otherwise useful land into swamps, so that it would not only be the space the reservoir takes up, but also the surrounding area that could be influenced. A big advantage of using an hydro storage facility in Denmark would be that during the nights where electrical power consumption is low, it would be ideal to store excess wind power using this method of energy storage. Unfortunately the disadvantages of using this method are bigger than the advantages, due to Denmark being a very flat country sites where a reservoir could be dammed up are few, if there are any. Advantages of using this method in California are that there are more opportunities for making reservoirs using natural sites. To use this form of energy storage it would be optimal to use excess energy from a sustainable energysource to store electrical energy, but as California seems to be mostly focusing on solar energy it does not match this application well as the energy would optimally be stored during the night. UC Merced Solar Test Facility Mon, August 3, 10:30am 12:00pm UC Merced is developing concentrated solar energy techniques using non-imaging optics. A the moment, there are three ongoing projects: 26

28 1- Concentrated Photovoltaics (CPV), that employ high efficiency multi junction solar cells to convert direct solar flux into electricity; 2- Concentrating Solar Thermal devices, that use concentrated sunlight to heat water; 3- and finally, Concentrated Solar Lighting, bringing natural light directly into buildings through optical fibers. Concentrated solar technologies are an optimal solution in California, where latitude and climate guarantee many bright days with no clouds, and good average insulation. 1- Concentrated photovoltaics Concentration is achieved through Compound Parabolic Concentrators (CPC), whose original SolFocus design has been improved: second generation concentrators are made of an achromatic parabolic primary mirror (aluminum covered in PMMA) and a secondary small dome (glass molded and silver coated), so that light impinging on the primary mirror is not focused onto the cell, but onto the secondary mirror. Ripples on the surface soften the focus, to avoid hot spots that could damage the cell. Acceptance is +/- 1.2 degrees, that requires tracking of the sun. The efficiency of the optical system is 86% (versus 70% of the first generation). There's a heat sink on the bottom, and air/water cooling is possible. Future improvements in design might involve hexagonal concentrators that would make the system more compact. Tests have been California Lighting Technology Center. Solar cells in use are InGaP/GaAs/Ge triple junction manufactured by Emcore, whose efficiency is currently 35%-40%. Cell size is 1 cm2. Concentrated flux is proven to improve the cell performance, until a maximum is reached. In III-V multi junctions as the one in use, the maximum is achieved at 500 suns flux (1 sun = 1 kw/m2): therefore, all concentration ratios are built around this value. Traditional Silicon cells can't stand this flux, and must work at lower concentrations (<100 suns). Main benefits of CPCs are: simple design, low cost materials, high efficiency and uniform flux distribution o the cell surface. The main problem is moisture that can diminish the efficiency of the cell, and heating related issues. Complications arise when several systems are built in series. 2- Solar Thermal In solar thermal systems, the parabolic collector surrounds a vacuum tube, inside which a fluid (mineral oil) loops around. Within 100 cycles, fluid temperature can increase from room temperature to 200 C. Huge arrays of 160 collectors can be used on industrial sites. These collectors have a broad acceptance angle (60 ) and do not require tracking, but is confined to small concentrations ( ). The system has a low efficiency (35%-45%), but is definitely cheaper than PV arrays. Main problems come from heating and weight of the system (when several CPCs are put together). Besides, a storage system is necessary. 3- Solar Lighting Finally, Solar Lighting devices gather sunlight that from outside is concentrated in mirrors 27

29 and conveyed to the interiors of the building, through a light pipe. This helps to reduce electricity demand (and related heat production). This technology is of easy constructability and allows to integrate natural and electric light (hybrid systems). Gallo Biogas Facility Monday, August 3rd, 1pm 3pm The fieldtrip took its beginning at "the world largest waterbed". A 7 acres big lagoon covered with plastic to make the inside anaerobic. It was build in 2004 and the input was 2,5 million dollars and in addition they got 1,5 million dollars in grant. Still there are 10 years payback time. Biogas production: Biogas production requires a steady environment for the bacteria to ferment and produce the gas. We are not sure of how much it differs between night and day here in Merced. But the climate differs from summer compared to winter, so maybe the gas production goes more slower in winter time. A possibility to optimize the gas production could be to use the heat from the power plant, so the temperature in the lagoon will rise. A big differences from the Danish climate is that in Denmark the temperature varieties more, so there is a need for heating the process. The system needs to be stable either at C (mesospheric) or at C and (hemophilic). The natural production of methane in the rumen of a cattle, takes place at 39 C degrees and ph at 6,5. By copying the naturally design of the rumen of cattle s, methane can be produced in human controlled conditions in biogas plants and used for energy sources. In this case the biogases are used in a combination for heat and power. The methane production actually only constitutes 65 % of the biogas produced. The rest is CO2. The energy content is in methane, and by then CO2 is not to be included in the biogas potential. When the biogas is burned it says that it is CO2 neutral. The picture shows the lagoon. The "bobbles" consist of methane produced by anaerobic bacteria. The lagoon have a capacity of 44,225,000 gallon (167,409 m3) of manure. Its an ongoing process, 24 hour a day. 28

30 Farm information: The farm is a "vertically integrated dairy, farming and cheese making enterprise". The production started way back in It now consists of acres (5666 hectar) of land. 500 people living at the area of the farm. They try to hire entire families to work at the farm gallons (378 m3) of milk are produced each day. 80 % of the milk is from their own livestock. The livestock are placed at 4 Farms. There are around 35,000 dry and diary cattle. There are only one site with a digester and at that particular site there are cattle. The missing smell at the biogas "plant" was explained by that the cattle was not feed with any artificial hormones. They are mainly feed with natural feed from the farm. All in all it is an extremely efficiency system. The farm has a very integrated and profitable system. Biogas in Denmark: In Denmark we have had biogas for many years. But in many years it has not been profitable for a farmer (not even groups of farmers) to invest in bio gas plants, even though they also will obtain a much more efficient manure, when degassed. The problem is the taxes. In our country Sweeden they have removed the taxes and implemented biogas into there grid of natural gas. Actually you can buy biogas for your vehicle at the gasoil stations. Some busses in Sweeden are right now driven by gas bought in Denmark. There are for sure a future for more biogas production in Denmark. We do have a huge lifestock of both cattle, pigs and chickens which all produce manure with high biogaspotential. By combination both manure and waste from households, you can obtain an even higher biogaspotential. In Denmark a huge amount of the waste are already used for CHP. UC Merced Cooling + energy tour/lecture Who: John Elliot, Assisant director of energy and sustanability at UC Merced. Tuesday, August 4th, 8:30am 10:00am They key issue for all the energy saving efforts here is the building energy efficiency. The basis for their energy efficiency plan is improving target numbers. The target numbers are from the other UC facilities and are corrected for climate and location differences so that there exists a base load on each of the 3 types of buildings (lab, residential, office). they have the target of reducing the energy consumption to 50% of the reference numbers. They have not done any lifecycle studies and are not considering the total carbon footprint. They are focusing on running costs. The energy savings runs in approximately $1 mio per year compared to other universities. The long term goal (2020) is to have a zero carbon footprint and to have all net consumption of energy from renewable sources. They will have a new solar plant on 1MW in photovoltaics installed on campus. the installation is done by a contractor and the university have committed to a 20 year power deal at fixed costs. The investment is therefore not done by the university. The power prices agreed upon is actually lower than the rates they get today from PG and E. 29

31 They have a challenge with the data centers as the power consumption in the data center is expected to increase by an order of magnitude. This will be a serious challenge for the target goal on decreasing the overall energy consumption. There is talks about building a offcampus centralized UC data center where different campuses would house their IT equipment. this would enable a location which is more suitable climate wise. The most important factor is the efficiency of the cooling system, which is more or less determined by the ambient temperature. At UC Merced they have a central cooling plant that supplies chilled water to the buildings for ac and to the data center for cooling. Around 25% of the electricity load of the campus is for the cooling system. It also uses 15% of the total water consumption for the evaporative condensation. (50% water is irrigation and rest 35% is tap water). The cooling plant runs at night and loads up a cold storage tank (2mio gal) for usage during the day. The lower nighttime temperature and the lower electricity rates amount to a cost reduction of 15-20% per year. The campus is planned to expand by a factor of 8 in the next years, so the cooling facility is oversized by a factor of 2. This have an impact on performance, but the cold store minimizes this disadvantage. They plan to build new facilities as the campus expands. They have a district heating system that runs with natural gas boilers. The heat load is unknown but from 25-75% of the cooling load. There is no heat recovery from that. The indoor climate is controlled mainly in therms of temperature and they have very advanced air mixing valves that can do both heating and cooling of the air. The valves are controlled for the individual rooms from a temperature sensor in each room. There is also a monitoring of the co2 level, but the adjustments based on that are limited. They have a datacenter for the administration but it is very inefficient because the room was initially planned as a telecommunications room (very light heatload) and the layout and infrastructure are not suitable for at data center. The room was cooled by two central hvac units, but the airflow was very mixed and the performance was poor. The return temperature of the cold water for the system was too high, which caused problems later in the chilled water system (the storage tank). John explained that in a new facility they are building, the data center consumes the same amount of energy as the rest of the squarefeet (9300m3) building. California Legislature, Sacramento Wednesday, August 5th, 2009, 10:30AM 12:30PM Discussion with: Kip Wiley, Senate Office of Research Lawrence Lingbloom, Chief Consultant to the Assembly Natural Resources Committee Kellie Smith, Consultant to the Senate Energy, Utilities 30

32 Tour with: Fred Keeley Today, we visited the most beautiful Capitol in Sacramento, California. California Legislature is represented by the Senate and the Assembly. o Senate consist of 40 members, each serving a 4 year term. Each Senate member can serve up to two appointments. o Assembly consist of 80 member, each serving 2 year term. Each Assembly member can serve up to three appointments. California Senate or Assembly can introduce a bill, however the number of bills by each group is limited. For instance, Senate can introduce up to 32 bills and Assembly members can introduce up to 40 bills. o The bill has to be in print for 3 days before it can be discussed during the official meeting. In Senate, to pass any bill there has to be 21 votes for it, while in an urgent matter Senate has to agree on it with 27 votes. 50% of bills that get introduced in the legislature never get passed. The state of California used to be a leader in environmental laws before the Federal Government overtook. Less than 20 years go, 1 Senator thought that the Earth is flat. California legislature first officially became active on the topic of energy efficiency in the beginning of 70s. o In the last 30 year, consumption of energy in California flattened out. 31

33 o There haven't been any standards enforced for data centers. o Sufficient number of data farms (large data center) are moving out from California. This is happening due to high cost of energy. o Renewable Energy Sources geothermal wind energy photovoltaic not hydroelectric because it is encouraging of building more dams that harm the environment. o By 2020, 1/3 of all power has to come from the renewable energy sources. This rule was proposed by our governor. o It takes 8 years from the time when a bill gets proposed to the time when the actual building occurs. California legislature favors photovoltaic purchase and installation in the following way: o subsidizes cost of the panel by returning 15% of the original cost o Federal government gives 30% back of the original cost o there is no property tax on this additional installation In 2001, California raised awareness of the public of their energy consumption. It worked really well. Most of energy in California comes from the following sources o Hydroelectric o Nuclear o Natural Gas o Photovoltaic There is currently an ongoing installation of photovoltaic panels being done in Mojave Desert o Current problems: mirrors get dusty from sand storms and vehicles that are operating near by rotating mechanical parts break down because of the sand that gets into them panels interfere with the native species A lot of people in California support renewable sources however some of them say "Not in my back yard approach" By 2050, California State needs to achieve 80% mark in renewable energy sources. California ISO Thursday, August 6th, 8am 12pm CAISO is the independent operator of California s electrical transmission system. It is a nonprofit corporation which is in control of running most of California s transmission system and to operate the electrical energy market. CAISO is regulated by FERC, who make sure CAISO follows the mandatory standards for operating an energy market and transmission. 32

34 The peak load in CAISO s transmission was MW in 2008 and the total production capacity is MW. CAISO makes forecasts for electrical power consumption for each day, which is then met with purchase of energy on the market operated by CAISO. CAISO does not directly control switching in the grid nor do they have direct control over production generators, but send out control messages to the different owners of the equipment that makes up the transmission system. The main features of the technology used for transportation of electricity have seen very little change since the beginning of its use. But with advantages in computing and communication technologies, running a reliable transmission system has become easier. These advancements have made a lot of new information available to the system operators, faster and more detailed than before. Using this information makes it possible to transport more energy through the existing network and in a more reliable way than before. The biggest challenges for CAISO is to get licenses to build new overhead transmission lines to new electrical production sites. This is mainly due to environmental reasons and in some cases lack of space. The process for building a new overhead line can take from 3 to 7 years, with the beurocracy process taking most of that time. With California s goal of increasing the part of renewable energy sources up to 33% of the total electrical energy production in 2020, it will be necessary to build new overhead lines to the new production sites needed to fulfill this requirement. Since the plan to increase use of renewable energy sources comes from the state, it is possible that getting licenses to build new overhead lines might be a quicker process for those lines connecting the production to the grid. Replacing overhead lines with underground cables is rarely feasible due to the cables being up to 10 times as expensive to buy and lay, and also in some cases the environmental concerns are similar of those for overhead lines. McClellan Nuclear Radiation Center. TRIGA Reactor. Thursday, August 6th, 2009, 13:00 16:00 When we arrived at the McClellan Nuclear Radiation Center, we were split into four groups that rotated through four stations. Each group was following a leader who was given a radiation meter. Each station had a employee who gave a presentation about particular site. Four stations included o Station #1: The reactor Station o Station #2: The reactor equipment room o Station #3: The radiography bays o Station #4: The radiography control room Nuclear Plants are not considered as renewable energy source. This particular center was built by the Airforce for the purpose of analyzing air crafts. The reactor began to operate in Reactor was located 25 ft deep and 7 feet in diameter container full of water. Reactor is capable of providing 2MW power 33