Perth & Kinross Council Small-Scale Renewables. Heat Pumps

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1 Perth & Kinross Council Small-Scale Renewables Heat Pumps

2 Renewable technologies Wind turbine Hydro turbine Solar photovoltaic panel Anaerobic digester Biomass boiler Solar hot water panel Heat pumps

3 Renewable Energy Sources

4 Heat Pumps Introduction Heat pump systems Ground Source Air Source Renewable Heat Incentive Conclusion

5 Heat Pumps A heat pump takes low temperature energy from the ground, water or the air and raises it to a higher more useful temperature. The amount of energy produced is greater than the energy used to drive the process. Electrical energy Energy from the ground, water or air 1 kw 3 kw 4 kw Output from the heat pump

6 Heat Pumps Able to convert solar energy stored in the ground, air or underground water into usable energy for heating and hot water Highly energy efficient solution for space and domestic water heating Alternative to a central heating boiler Source energy is totally free and inexhaustible Low carbon emissions, low running costs

7 Heat Pumps How does it work? Like a refrigerator A fridge takes heat from the food and air inside and passes it to a radiator at the back of the unit Uses same refrigeration cycle as a heat pump A heat pump removes heat from heat source and moves it to the heating system inside homes and businesses

8 Heat Pumps Operation

9 Heat Pumps System Types Ground Source Uses a collector buried in the ground to absorb latent heat Pipes with water/glycol circulated Collector can be mounted horizontally (requires large land area) or vertically (circa 90m deep) Air Source Water Source Reversible ground Collects heat from the external air Can be installed indoors or outdoors No collectors to install Uses two drilled wells (extraction & absorption) to absorb latent heat Wells typically drilled 20m Requires specific flow rates Has specialist requirements Heating and cooling models available within air and source systems

10 Air Source or Ground Source Air Source Lower capital cost Simpler to install Appearance Some external noise Performance sensitive to outside temperature Water Source Higher capital cost Disruption during installation Visually unobtrusive Quiet Performance less (not) sensitive to outside temperature

11 Heat Pumps Ground Source Collects Heat Energy from the ground surrounding the building Various types of ground collector: Horizontal, closed or open loop, borehole probes and energy piles Delivers the Heat Energy to the building via the internally sited Heat Pump Borehole probes guarantee the most stable source temperature Normal output temperature typically º C, lower than standard radiators (71-80 º C)

12 Heat Pumps Ground Source collector Boreholes Can be used when space is confined or large capacity is required Efficiency benefit equals lower temperature fluctuation Boreholes typically m deep with 32mm or 40mm dia pipes

13 Heat Pumps Ground Source collector Boreholes typically 200mm dia Single or double u probe configuration 17 25m per kw (depending on ground type)

14 Heat Pumps Ground Source collector Horizontal Collectors Slinkies Can be laid vertically or horizontal Normally 32mm dia MD/HDPE pipe Depth 1.2m Spacing 3 5m apart Lower cost than boreholes Requires larger land area Less excavation & Lower heat extraction 10m of trench per kw (varies with ground type)

15 Heat Pumps Ground Source collector Horizontal Collectors - Trench

16 Heat Pumps Ground Source collector Pile/foundation collectors: Energy piles collect heat from the foundations of a building via closed loop probes located within the piled foundations A building can potentially gain approximately 25% of it s heating requirement from the foundations. The remaining source load can be provided from other ground sources or an air source / energy pile hybrid system Can be a very economic means of gaining source load

17 Heat Pumps Equipment

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19 Heat Pumps Air Source Use latent heat in the ambient air as the heat source Can be installed indoors or outdoors. Needs planning permission or prior notification. Operational down to 20 C Variability in temperature affects CoP and output throughout the year Good CoP s achieved in UK due to relatively high ambient winter air temperatures circa 4 C (06/ C)

20 Heat Pumps - Air Source Heat extracted from outside air Cheaper and simpler installation than GSHP External unit (evaporator) similar to the external unit of an air conditioning system Output type Air-air heat pump or air-water Air-air heat pump Warm air distributed by fans Suitable where exterior space is limited Potential alternative when installing a wet system is problematic Utilised for heating, cooling or both Heating performance drops at low outside temperatures

21 Heat Pumps Heat pumps can provide both space heating and domestic hot water 35-55ºC water temperature Radiators Sub-optimal flow temperatures required, i.e. 55ºC or above Compromises heat pump efficiency Require larger surface area than for conventional boilers Need to be oversized for use with heat pumps

22 Heat Pump - Co-efficient of Performance CoP affected by: Heat source temperature Heating water temperature (flow/return temperatures) Additional supplementary heating CoP continually varies Spot measure of performance at optimal conditions Much like car mpg figures

23 Heat Pump - Co-efficient of Performance

24 Heat Pumps System Selection Not all buildings are suitable for a heat pump! Buildings should be well insulated Old buildings with solid walls can be a problem Heat pumps are designed to be energy efficient and run at low temperatures Energy wastage needs to be reduced by insulation Important to carry out accurate heat loss calculation

25 Heat Pumps What s the issue? It s not the AGE - It s thermal efficiency NOT suitable!!!

26 Heat Pumps - Considerations Although a significant proportion of the energy from a heat pump is free from the environment, the electricity to run the heat pump still has to be paid for! For retro fit installations, it would be reasonable to assume that an air source heat pump will have similar running costs to a good (and properly optimised) condensing boiler For new build, running costs of up to 25% better than a gas boiler could be expected However - no safety issues, no need to replace after 8 10 years Running cost savings against oil or LPG will be more significant No storage or bulk delivery issues

27 Heating type Heat pump and other heating installations: efficiency comparison Typical average efficiency (heating & hot water) Typical fuel unit cost (p/kwh) Cost per kwh delivered (p) ** Running cost for 15,000 kwh/yr Condensing gas boiler (A rated) 90% Existing gas boiler 80% Condensing oil boiler 90% 5.8 (60p/litre) Existing oil boiler 80% 5.8 (60p/litre) , Electric storage heating 100% Heat pump (worst case scenario) Heat pump (better scenario) Heat pump (good scenario) 250% (COP 2.5) 8.16* % (COP 3) 8.16* % (COP 3.5) 8.16*

28 Effect of heat pump efficiency

29 Heat Pumps Case Study Ground source Heat Pump size Net Energy Delivered by GSHP Potential RHI income 12Kw 26,000 kwh 1,118 per Annum Ground source Heat Pump size Net Energy Delivered by GSHP Potential RHI income 30Kw 87,000 kw/h 3,741 per Annum Number of other areas to consider: Depreciation, Service and Maintenance costs, Tax advantages, etc, etc.

30 Assessing Alternative Projects Where do I start? What do I need to consider? How much do they cost? What is the likely return? Which is the best one for my circumstance?

31 Pre Feasibility Study What should be considered? Investigate capital costs A site survey, including detailed photographic survey and technical measurements Comparisons between different technologies Compare options for ground source or air source heat pumps Examination of any likely environmental or planning issues Prepare estimates of heat generation and payback from renewable heat incentive Clear advice on what to do next

32 Assessing Alternative Projects Where do I start? What do I need to consider? How much do they cost? What is the likely return? Which is the best one for my circumstance? Prefeasibility study should narrow down options available Assess the likely returns over 20 years? How realistic are the assumptions I am given? Where are extra costs likely to appear?

33 Microgeneration Certification Scheme Has your scheme installer got Microgeneration Certification Scheme approval (MCS)? The Microgeneration Certification Scheme (MCS) is an independent scheme that certifies microgeneration products and installers in accordance with consistent standards. It is designed to evaluate microgeneration products and installers against strict criteria providing greater protection for consumers. MCS applies to installations (product and installer) in the 0-50kW range. Checking that the equipment and installation company you are using has MCS accreditation is essential, and best done at the very outset of any project.

34 Microgeneration Certification Scheme The MCS was designed to raise the level of quality starting with the plant and extending to the installers. The legal definition of Micro generation applied to products producing: <50kW of power generation or <45kW of renewable heat. MCS technologies include: Solar PV Wind power Solar collectors Biomass CHP & Heat pumps including: GSHP Ground Source & ASHP Air Source.

35 Microgeneration Certification Scheme MCS has now become a prerequisite for many schemes and also for government tender lists. For manufacturers the process is long winded and expensive. It involves factory procedure inspections and witness tests. For installers it involves inspections of compliance, stability and technical ability to design, install and follow up. e.g. A heat pump must achieve a specific CoP and it must have a full set of test results.

36 Microgeneration Certification Scheme Remember, clean energy cashbacks (Feed-in Tariffs) and renewable heat incentives are only available to those installations using MCS approved products and installation companies. All MCS registered suppliers and installers can be checked on the MCS web site:

37 Financial Assistance A business to claim 100% first-year capital allowances on their spending on qualifying plant and machinery. Information available on web site - Carbon Trust Interest Free Loans - Funding has been reduced and loan offering to be withdrawn from 28 March 2011 New loan scheme to be launched in April 2011 backed by the Carbon Trust who will assess cost, energy and carbon savings. East of Scotland Investment Fund (ESIF) loan scheme can provide finance for projects up to 50,000

38 Renewable Heat Incentive The Renewable Heat Incentive is the equivalent proposal to the feed-in-tariff for heat generating renewable technologies to be introduced from July 2011 Range of technologies and fuel sources are supported: Biomass Heating Systems Ground-source heat pumps Solar thermal The scheme at present does not support: Air source heat pumps

39 Renewable Heat Incentive Tariff Name Eligible technology Eligible sizes Tariff rate (p/kwh) Tariff Duration (years) Support Calculation Small Biomass Medium Biomass Solid Bio Mass; Municipal Waste (including CHP) Less than 200 kw Greater than 200 kw less than 1000 kw Tier 1: 7.6 Tier 2: 1.9 Tier 1: 4.7 Tier 2: Metering tier 1 applies annually to the first 1,314 kw heat produced after this level moves to the tier 2 rate i.e. kw x 1,314 Large Biomass Greater than 1000 kw 2.6 Metering Small ground Source Large ground source Ground Source heat pumps Water-source heat pumps; deep geothermal Less than 100kW 4.3 Greater and including 100 kw 3 20 Metering Solar Thermal Solar Thermal Less than 200kW Metering Biomethane Biomethane injection and biogas Bio-methane all scales, biogas combustion less than 200 kw Metering

40 Renewable Heat Incentive RHI commences July 2011 for commercial installations Designed to provide a 12% rate of return All Installations after 15 July 2009 are eligible Public sector organisations are eligible Feasible to remove & replace existing systems to receive tariff Not possible to receive any grant funding along with RHI Equipment under 45kW must be MCS accredited New Equipment only no second hand/refurbished Paid quarterly over 20 years - indexed linked Supported by 860M Government funding

41 Renewable Heat Incentive Domestic customers are considered separately with a proposed RHI Premium Payment from July 2011 Indicative payments available: Solar Thermal Air Source Heat Pumps Biomass boilers Ground Source Heat Pumps 300/unit 850/unit 950/unit 1250/unit

42 Conclusions Impartial Advice - the best renewable energy option for any building depends on its situation, construction, condition, age and how it is used. Seek information and independent impartial advice on what would be the best options for you. Home Improvement First - before investing in renewable energy technology, make all possible energy efficiency improvements to your building. Choose a Heating Option - The options are a biomass boiler, a heat pump or solar thermal panels. In many domestic situations a wood pellet boiler may fit the bill. A heat pump needs a very well insulated and draughtproof house as it is less efficient when worked hard. Solar water heating is nice to have and cheaper to install but has a very long payback unless you use much more hot water in summer than in winter.

43 Conclusions The Right Price - Obtain three comparable quotes for any installation. The cheapest quote may represent the best option BUT it might be achieved by cutting corners on quality, warranty terms, aesthetics or the user-friendliness of the system. Incentives -Take the incentives into account as well as the expected running cost savings. The Government s Feed in Tariff (FiT) scheme and the Renewable Heat Incentive (RHI) present potentially lucrative possibilities. Never take a performance projection at face value