Bill Pyke Hilbre Consulting Limited October 2012

Transcription

1 Alternative Energy Sources Bill Pyke Hilbre Consulting Limited October 2012 Delivered on to: Local Solutions 1

2 Microgeneration Categories 2

3 Micro-options Domestic wind turbines Solar panels Micro CHP Ground source heat pumps (GSHP) Micro-hydroelectricity Biomass Microgrids 3

4 Current Status Less than 100,000 microgeneration installations in the UK (of which most are solar water heaters installed pre-2000) Few microgeneration technologies are cost-effective at present. Notable exceptions are biomass heating and ground source heat pumps which can be cost effective when compared with electric heating systems Small commercial scale (sub 50kW) CHP units are borderline cost effective at present without a technology breakthrough. Most of the microgen technologies are a decade away from mass market commercialisation 4 Source: Energy Saving Trust

5 Recent Changes Historically the barriers to entry have been high front-end cost and long payback Government initiatives (grants, tax incentives) and technology and mass production of systems now bringing microgen systems present a more attractive commercial proposition Concern over increasing fossil fuels costs can tip balance in favour of microgen Increasing concerns about CO 2 emissions and targets 5

6 Objectives By 2050 micogeneration:- Could potentially provide 30-40% of the UK's total electricity needs Could reduce CO 2 emissions by 15% per year Large proportion of homes in the UK could be generating their own energy, saving tonnes of carbon dioxide emissions and helping to prevent climate change." According to estimates, eight million micro-chp units could be in homes by 2020, supplying a third of a household's power. 6 Source: Energy Saving Trust

7 Barriers High front-end costs Technologies still not fully developed for mass appeal Legislation/Regulation/Planning often against permission /approval Subsidies/Funding small, complicated Incentive tariffs- feed-in tariff is inadequate Skills/Training Education/Awareness/Lack of clear and widespread information 7

8 Wind and Microgeneration Ideally suited to U.K., particularly Scotland Operate at wind speeds at >5m/sec High initial cost outlays. term. Small wind systems are generally not cost effective at present. Mass-commercialisation could occur circa Could supply 4% of UK electricity requirement Could reduce domestic CO 2 emissions by 6%. 8

9 Wind CHP Good in areas of wind speeds >10m/sec Performance band width from 4 to about 15m/sec wind speed, Nominally rated at 1kW at a given wind speed of 12 m/sec net effect is a potential saving of up to 30% overall against the UK average 'domestic' electricity bill e.g. 3,200 kwh per annum 9

10 Domestic Wind Microgeneration 10 Source:

11 Wind Power Advantages & Disadvantages Advantages Relatively low front-end( installation cost. British DIY retailer sell 1kW Windsave turbines from 1,500) Low running /maintenance costs. Can sell electricity to the Grid Disadvantages Visually unattractive Variable wind Often ineffective in built-up and suburban area Often need planning permission 11

12 Solar Microgeneration High uptake of Photovoltaics (PVs) in U.K. at present. Feed-in tariff 6 panels of solar PVs on a typical new three-bedroom house could reduce that household's carbon emissions by over 20% Solar PV panels don't need direct sunlight to work as electricity is generated from daylight. So if it s cloudy, the power output may be slightly lower but nonetheless it will still be there This technology could supply almost 4% of UK electricity demands Reduce domestic sector CO 2 emissions by up to 3%. 12

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14 Solar (Heat) Power Advantages & Disadvantages Advantages Silent Low maintenance Disadvantages 14 Requires south-facing, structural strong roof for optimum effect Often need planning permission

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16 Solar (Heat) Power Advantages & Disadvantages Advantages Silent Low maintenance Disadvantages 16 Requires south-facing, structural strong roof for optimum effect Often need planning permission

17 Solar (Photovaltaic) Power Advantages & Disadvantages Advantages Silent Low maintenance Disadvantages X need planning permission 17

18 Micro-CHP Concepts Capturing waste heat- 30 to 40% of the primary energy ends up as electricity, but 60 to 70% goes up the chimney! Embedded Generation Net metering- taking from/giving to the grid 18

19 Micro CHP Power Plants Three engine types: Internal combustion engines, which are already on the market, with more than 6000 installed in Germany and around 8000 in total in the EU External combustion engines, typically Stirling engines, organic Rankine cycle engines or steam engines. The first commercial sale of Stirling engines occurred in 2005 Fuel cells, which are in the development and demonstration stages 19

20 Micro CHP Market Potential Main target market for Micro-CHP is the domestic mass market as are replacement for conventional gas boilers in domestic dwellings, with the Micro-CHP unit operating in a heat-led mode There are approximately 17 million gas-fired central heating systems in Great Britain and approximately 1.3 million gas boilers are sold a year, indicating a large potential market for Micro-CHP 20 Source: Cogen Europe

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22 WhisperGen Micro CHP Average home uses around 18,000kWh per year Can generate 3,000kWh of electricity per year Costs about 3,000 to buy and install Reduces carbon dioxide emissions by an average of 1.5 tonnes per year Saves household energy bills of about 150 per year 22

23 Micro CHP Process The Stirling Engine-an External Combustion Engine Heats up four cylinders, each of which contains nitrogen gas and a piston. The gas expands as it warms up, pushing the pistons down-cooler central heating water underneath sends piston up. Pistons which go up and down 1,600 times a minute, turns generator producing 850 watts and also producing a constant supply of hot water at 65 0 C Savings of 20% possible 23

24 Micro CHP Advantages & Disadvantages Advantages +Power & Electricity always available +High efficiency (>70%) +Surplus electricity can be sold to Grid Disadvantage - Relatively high installation cost - Needs gas supply -best suited to communal developments 24

25 Ground Source Heat Pumps (GSHP) Ground source heat pumps work by taking energy from the ground and using it in conjunction with a refrigerant circuit This allows temperatures taken from the earth to be boosted to a useful level for the provision of home heating and hot water 25

26 Ground Source Heat Pumps (GSHP) 26

27 Ground Source Heat Pump 27

28 Heat Transfer Principles Compressing gases increases temperature Expanding (decompressed) gases decrease temperature A heat pump contains a gas-filled loop Incoming warmer circulating fluid is put through the heat pump. Compression heats the gas which in turn heats the water supply Decompressed fluid is cooler and picks up heat when circulated through an area (warmer ground as a heat source) 28

29 GSHP Process (1) 29 Source: Worcester-Bosch

30 GSHP Process (2) A closed loop GSHP installation comprises of plastic piping buried in the ground and connected to a heat pump Brine/water-antifreeze mixture is passed around an 800 metre looped pipe where it absorbs heat from the ground The fluid flows into an electrically powered heat pump, comprising a compressor and a pair of heat exchangers before discharging back to the underground loop 30

31 Ground Source Heat Pump Facts The Ground Source Heat Pump System (GSHP) delivers four times as much heat energy as it consumes as electrical energy Extracts heat from the ground where the year round ambient temperatures is C The low level heat from the ground is concentrated via a compressor into high-level heat stored in an indoor hot water tank Uptake in new houses in Switzerland 33%, in Sweden 70% 31

32 Ground Source Heat Pumps (GSHP) Advantages & Disadvantages Advantages +Carbon savings of 30-35% (more if the pump is powered by renewable electricity) +Life expectancy of 40+ years Disadvantages - Relatively high installation cost ( 10-20K), payback 15-20years - Electricity drives the heat pump - Large site area required for horizontal pipe installation - Use of refrigerants 32

33 Micro Hydroelectricity Utilising small stream flow Small-scale plant serving a home or small group of homes Hi-tech water wheels now available 33

34 Micro Hydroelectricity Advantages & Disadvantages Advantages +Reliable power-as long as the water keeps flowing +High efficiency (>70%) +Surplus electricity can be sold to Grid Disadvantages - Relatively high installation cost - Electricity drives the heat pump - Large site area required for horizontal pipe installation - Use of refrigerants 34

35 Microgeneration: Biomass Reliant on renewable sources such as wood pellets Most common installation are wood-burning stoves 35

36 Biomass Sources Forest products: salvageable dead wood, logging residues, and excess polewood Coppice Wood Urban wood waste and mill residues: mill residues, urban wood waste, and construction and demolition debris Agricultural residue: wheat straw and corn remnants Energy crops: switch grass, hybrid poplar and hybrid willow Biowaste, Landfill Sites 36

37 Biomass Advantages & Disadvantages Advantages +Low start-up costs +Established technology Disadvantages 37 - Fuel costs -Storage Requirement - Dry feed required, heating to reduce moisture content -Residues

38 Microgrids A collection of small generators for a collection of users in close proximity. A small community networks that supply electricity and heat Small networks of power generators in "microgrids" could transform the electricity network in the way that the net changed distributed communication They could make substantial savings, and emissions cuts with no major changes to lifestyles Could save something like 20 to 30% of emissions 38 Source: Southampton University

39 Microgrid Advantages Micromanaging supply and demand Generator sizes are similar to loads Smaller networks mean ways to store unused power can be introduced, something that does not happen in large networks Smart grid using sophisticated software and grid computing technologies 39

40 Technology Set-up cost Annual Saving Payback in Years 1kW Solar PV 5, kW Solar PV 15, kW Wind 3, Turbine 2.5kW Wind 10, Turbine 1kW Hydro 4, kW Hydro 12, kW boiler + GSHP 17,

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42 Web References Solar (heat) Solar (Photovoltaic) Ground Source Heat Pumps Wind Combined Heat and Power Micro Hydroelectricity 42