Renewable energy in Scotland

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The production of renewable energy in Scotland is an issue that has come to the fore in technical, economic and political terms during the opening years of the 21st century.^[1] The natural resource base is extraordinary by European, and even global standards. In addition to an existing installed capacity of 1.3 Gigawatts (GW) of hydro-electric schemes, Scotland has an estimated potential of 36.5 GW for wind and 7.5 GW tidal power, 25% of the estimated total capacity for the European Union and up to 14 GW of wave power potential (10% of the EU capacity).^[2][3] The renewable electricity generating capacity may be 60 GW or more, considerably greater than the existing capacity from all fuel sources of 10.3 GW.^[2][4]

Much of this potential remains untapped, but continuing improvements in engineering are enabling more of the resource to be utilised. Fears regarding 'Peak Oil' and climate change have driven the subject high up the political agenda. Although the finances of many projects remain either speculative or dependent on subsidies, it is likely that there has been a significant, and in all likelihood long-term change, in the underpinning economics.^[5]

In addition to planned increases in generating capacity from renewable sources, various related schemes to reduce carbon emissions are being researched.^[6] Although there is significant support from the public, private and community-led sectors, concerns about the impact of the technologies on the natural environment have been expressed. There is also an emerging political debate about the relationship between the siting, and the ownership and control of these widely distributed resources.^[7]

Renewable Energy
Biofuels Biomass Hydro power Geothermal power Solar power Tidal power Wave power Wind power
Sustainable Technology

Contents 1 Realisation of the potential 2 Wind power 3 Wave power 4 Tidal power 5 Hydro-electric power 6 Biofuels 6.1 Biodiesel 6.2 Anaerobic digestion and landfill gas 6.3 Solid biomass 7 Micro systems 7.1 Solar energy 7.2 Geothermal energy 8 Other renewable options 9 Other means of reducing carbon emissions 9.1 Carbon offsetting 9.2 Carbon sequestration 9.3 'Clean coal' technology 9.4 Incineration 9.5 Hydrogen 9.6 Nuclear power 10 Local vs national concerns 11 Promotion of renewables 12 Summary of Scotland's resource potential 13 See also 14 Main references 15 Citations and footnotes 16 External links

[edit] Realisation of the potential

In January 2006 the total installed electrical generating capacity from all forms of renewable energy was less than 2 GW, about a fifth of the total electrical production.^[4] By January 2007 wind power capacity, which has been growing rapidly, reached 1 GW capacity, and the total for renewables had grown to to over 2.3 GW^[8] representing about 13% of total output in 2006.^[9][10] It should be borne in mind that electricity production is only part of the overall energy use budget. In 2002, Scotland consumed a total of 175 TWh of energy in all forms, some 2% less than 1990. Of this, only 20% was consumed in the form of electricity by end users, the great majority of energy consumption being from the utilisation of oil (41%) and gas (36%).^[11][12]

Scotland also has significant quantities of fossil fuel deposits, including 62.4% of the EU's proven reserves of oil, 12.5% of the EU's proven reserves of gas and 69% of UK coal reserves.^[3] Nonetheless, the Scottish Executive have set ambitious targets for renewable energy production. The aim is for 18% of Scotland's electricity production to be generated by renewable sources by 2010, rising to 40% by 2020.^[13]

An important reason for pursuing this ambition is growing international concern about human-induced climate change. The Royal Commission on Environmental Pollution's proposal that carbon dioxide emissions should be reduced by 60% were incorporated into the UK government's 2003 Energy White Paper.^[2] The 2006 Stern Review proposed a 55% reduction by 2030.^[14] The recent Intergovernmental Panel on Climate Change's Fourth Assessment Report^[15] has further increased the profile of the issue.^[16]

[edit] Wind power

Wind power is a renewable technology and produces no greenhouse gases during operation, although inevitably some are produced during construction and transport. The precise amounts involved are a matter of controversy. Manufacturers typically state that carbon emissions are 'paid back' within 3-18 months of production, but recent research claims that turbines located on peat bogs create incidental emissions that may increase this to 8 years or more.^[17]

Wind turbines are the fastest growing of the renewable energy technologies in Scotland. Most turbines in the EU produce electricity at an average of 25% of their rated maximum power due to the intermittency of wind resources,^[18] but Scotland's wind regime provides average of 40% or higher on the west and northern coasts. A small wind farm on Shetland with three Vestas V47 660 kW turbines recently achieved a world record of 58% capacity over the course of a year.^[19]

Nevertheless the siting of turbines has become a controversial issue amongst those concerned about the value of natural landscapes.^[20] It is estimated that 11.5 GW of onshore wind potential exists, enough to provide 45 TWh of energy. More than double this amount exists on offshore sites^[2] where mean wind speeds are greater than on land.^[21] The total offshore potential is estimated at 25 GW, and although more expensive to install could be enough to provide almost half the total energy used in Scotland.^[2] The first offshore turbines are under commissioning for Talisman Energy, who are installing two large machines 25 km offshore adjacent to the Beatrice oilfield. These turbines are 88 m high and the blades 63 m long and will have a capacity of 5 MW each, making them the largest in the world.^[22][23]

[edit] Wave power

Wave power uses the energy in waves, and various systems are under development at present aimed at harnessing the enormous potential available off Scotland's coasts. Ocean Power Delivery are an Edinburgh-based company whose Pelamis system has been tested off Orkney and Portugal. These devices are 150 m long, 3.5 m diameter floating tubes which capture the mechanical action of the waves. Future wave farm projects could involve an arrangement of interlinked 750 kW machines connected to shore by a subsea transmission cable.^[24]

Another approach is used by the LIMPET 500 (Land Installed Marine Power Energy Transformer) energy converter installed on the island of Islay by Wavegen Ltd. It is a shore-based unit and generates power when waves run up the beach, creating pressure inside an inclined oscillating water column. This in turn creates pneumatic power which drives twin 250 kW the generators. LIMPET was opened in 2001 and is the world's first commercial scale wave-energy device. The manufacturers are now developing a larger system in the Faroe Islands.^[25][26]

The European Marine Energy Centre (EMEC) based in Orkney is a new Scottish Executive-backed research facility. They have installed a wave testing system at Billia Croo on the Orkney mainland and a tidal power testing station on the nearby island of Eday.^[27]

Funding for the UK's first wave farm was announced by the Scottish Executive on February 22, 2007. It will be the world's largest, with a capacity of 3 MW generated by four Pelamis machines and a cost of over 4 million pounds.^[28] The funding is part of a new £13 million funding package for marine power projects in Scotland that will also support developments to Aquamarine's Oyster and Ocean Power Technology's PowerBuoy wave systems, AWS Ocean Energy's sub-sea wave devices, ScotRenewables' 1.2 MW floating rotor device, Cleantechcom's tidal surge plans for the Churchill barriers between various Orkney islands, the Open Hydro tidal ring turbines, and further developments to the Wavegen system proposed for Lewis as well as a further £2.5 million for EMEC.^[29]

[edit] Tidal power

Unlike wind and wave, tidal power is an inherently predictable source. However the technology is in its infancy and numerous devices are in the prototype stages. Today we know that a tall tubular tower with three blades attached to it is the typical profile of a wind turbine, but twenty-five years ago there were a wide variety of different systems being tested.^[30] This is the current situation with regard to tidal power. Some systems capture energy from the tides in a vertical direction. Tides come in, raise water levels in a basin, and tides roll out. At lower stages of the tide, the water in the basin is discharged through a turbine. Tidal stream power captures energy from the flow of tides, usually using underwater plant resembling a small wind turbine. To date the only installed tidal power plant of any size is the 240MW rated barrage scheme at the Rance Estuary in Brittany, which has been operating successfully for more than 25 years, although there are a number of other much smaller projects around the world.^[31]

The Pentland Firth between Orkney and mainland Scotland has been described as the 'Saudi Arabia of tidal power'^[32] and may be capable of generating up to 10 GW.^[33] Several other tidal sites with considerable potential exist in the Orkney archipelago.^[34] Tidal races on the west coast at Kyle Rhea between Skye and Lochalsh, the Grey Dog north of Scarba, the Dorus Mor off Crinan and the Gulf of Corryvreckan also offer significant prospects.^[35][33]

[edit] Hydro-electric power

Scotland has 85% of the UK's hydroelectric energy resource,^[36] much of it developed by the North of Scotland Hydro-Electric Board in the 1950s. Current capacity is 1.33 GW^[4] and includes major developments such as the 120 MW Breadalbane scheme and the 245 MW Tummel system. It is estimated that little more than another 0.3 GW remains available to develop.^[2] There is further potential for new pump storage schemes that would work well with intermittent sources of power such as wind and wave. Existing examples include the 440 MW Ben Cruachan and 300 MW Falls of Foyers schemes.^[37]

[edit] Biofuels

[edit] Biodiesel

Various biodiesel schemes exist at present, and as with most renewables, interest is growing in the subject. Westray Development Trust operate a biodiesel vehicle fueled by the residual vegetable oils from the Orkney archipelago fish and chip outlets.^[38] On a larger scale Argent Energy's plant in Motherwell recycles tallow and used cooking oil, to produce 50 million litres of biodiesel per annum.^[39]

A major benefit of biodiesel is lower carbon emissions, although the energy balance of liquid biofuels is a matter of controversy.^[40] Research is being undertaken into converting oil seed rape into biodiesel,^[38] and the European biofuels directive is intended to create a renewable portion of 5.75% Europe's transport fuel by 2010. However, there is only enough used vegetable oil in the UK to contribute 0.38% of current road fuel demand, and even if all the arable land in the UK were turned over to biofuel crops this would still only satisfy 22% of the existing requirement for road transport. Serious concerns regarding the ethics of growing biodiesel in developing countries and importing the fuel to Europe have been raised on the grounds that they may replace much needed food crops. Converting any mainstream transport system to a renewable one also involves the conundrum that for consumers to use it the infrastructure must be in place, but high levels of use may be required to finance the infrastructure.^[5] Developments are thus slow at present and renewably powered vehicles very much the exception.

Ethanol cannot be commercially produced as a fuel in Scotland, for the time being at least.^[41]

[edit] Anaerobic digestion and landfill gas

Biogas, or landfill gas, is a biofuel produced through the intermediary stage of anaerobic digestion consisting mainly of 45–90% biologically produced methane and carbon dioxide. In early 2007 a thermophilic anaerobic digesiton facility was commissioned in Stornoway in the Western Isles. SEPA & the Renewable Energy Association are also leading the way towards the establishment of a digestate standard to facilitate the use of solid outputs from digesters on land. Anaerobic digestion and mechanical biological treatment facilities have been planned at a number of other locations in Scotland, such as Westray.^[42]

It is estimated that 0.4 GW of generating capacity might be available from agricultural waste in Scotland.^[2] The Scottish Executive and SEPA has funded seven small scale farm trial plants with the British anaerobic digestion company Greenfinch in Southwest Scotland.^[43]

Landfill sites have the potential for a further 0.07 GW. Landfill sites such as the Avondale Landfill in Falkirk utilise landfill gas (biogas) to the maximum extent.

[edit] Solid biomass

Wood fuel almost certainly exceeds hydroelectric and wind as the largest source of renewable energy at present; and Scotland's forests, which currently make up 60% of the UK resource base,^[44] could provide up to 1 million tonnes of wood fuel per annum.^[26] The biomass energy supply in Scotland could reach 450 MW or higher in coming years, (predominantly from wood), with power stations requiring 4,500-5,000 oven dry tonnes per annum per megawatt of generating capacity.^[44] The energy company E.ON intend to construct a 44 MW biomass power station at Lockerbie using locally sourced crops.^[45] The Forestry Commission are developing a Scottish Biomass Action Plan in conjunction with the Scottish Executive, and the latter is expected to provide a £7.5 million grant scheme to support biomass energy. There is growing demand for automatic wood pellet boilers which can be as convenient to use as conventional central heating systems, and which may be cheaper to run as well as being carbon neutral.^[26]

There is also local potential for energy crops such as short-rotation willow or poplar coppice, michanthus energy grass, agricultural wastes such as straw and manure, and forestry residues.^[26][46] These crops could provide 0.8 GW of generating capacity.^[2]

[edit] Micro systems

The Energy Savings Trust estimate that micro-generation could provide 30-40% of the UK's electricity demand by 2050^[47] although the current Scottish output is trivial. In May 2006 Communities Minister Malcolm Chisholm launched a Planning Advice Note aimed at promoting micro-renewables.^[48] Small-scale 'wind2heat' projects in remoter rural areas have proven to be successful^[49] as have various other local schemes such as air source heat pumps.^[50]

Whisky distilleries may have a locally important part to play. Caithness Heat and Power have announced plans to tackle fuel poverty in Wick by utilising a wood chip CHP scheme in partnership with the Old Pulteney Distillery.^[51]

[edit] Solar energy

Despite Scotland's relatively low level of sunshine hours, solar panels can work effectively as they are capable of producing hot water even in cloudy weather.^[52][53] The technology was developed in the 1970s and is well-established with various installers in place such as Solar Power Scotland of Montrose, although AES Solar based in Forres (who provided the panels for the Scottish Parliament building)^[54] are Scotland's only manufacturer.

There are few examples of photovoltaic cells in Scotland as the price is not currently competitive. The largest installation in Scotland is a 21 kWp system at the Sir E. Scott secondary school in Tarbert, Harris.^[55] The UK's practicable resource is estimated at 7.2 TWh per annum,^[47] which in the Scottish context is the approximate equivalent of 0.07GW or less of installed capacity.

[edit] Geothermal energy

Geothermal energy is obtained by tapping the heat of the earth itself. Most systems in Scotland provide heating through a ground source heat pump which brings energy to the surface via shallow pipe works. An example is the Glenalmond Street project in Shettleston, which uses a combination of solar and geothermal energy to heat 16 houses. Water in a coal mine 100 metres below ground level is heated by geothermal energy and maintained at a temperature of about 12°C (54°F) throughout the year. The warmed water is raised and passed through a heat pump, boosting the temperature to 55 °C (131 °F), and is then distributed to the houses providing heating to radiators.^[56]

Although the pumps may not be powered from renewable sources, up to four times the energy used can be recovered. Installation costs can vary from £7,000 to £10,000, and grants may be available from the Scottish Community and Householders Renewables Initiative operated by HICEC for domestic properties to up to a maximum of £4,000.^[57] Perhaps up to 7.6 TWh of energy is available on an annual basis from this source.^[58]

[edit] Other renewable options

Various other ideas for renewable energy in the early stages of development, such as ocean thermal energy conversion, deep lake water cooling, and blue energy, have received little attention in Scotland, presumably because the potential is so significant for less speculative technologies.

[edit] Other means of reducing carbon emissions

It is clear that if carbon emissions are to be reduced, a combination of increased production from renewables and decreased consumption of energy in general and fossil fuels in particular will be required.^[59] On the latter front, Gordon Brown, the UK Chancellor of the Exchequer, announced in November 2006 that within a decade all new houses would have to be 'zero carbon'.^[60] A variety of other options exist, most of which may impact the development of renewable technologies even if they are not means of producing energy from renewable sources themselves.

[edit] Carbon offsetting

This involves individuals or organisations compensating for their use of fossil fuels by making payments to projects that aim to neutralise the impact of these carbon emissions. Although the idea has become fashionable, the theory of 'carbon offsetting' has received serious criticism of late.^[61][62]

Nonetheless, a credible option may be to plant trees within the local bioregion and maintain the forest on a permanent basis, thus locking up carbon produced by burning fossil fuels. In British growing conditions this method can compensate for 2 tonnes of carbon per hectare planted over a 100 year period. Thus a 60 ha plantation could uptake 3,000 tonnes of carbon over twenty-five years.^[63] This is the equivalent of 10,000 tonnes of carbon dioxide.^[64] The weaknesses of the approach include uncertainty as to whether the planting might have occurred anyway and who, in the future, will ensure permanence. However, there is likely to be a greater level of credibility inherent in a nearby and visible scheme than in a far-distant one.

[edit] Carbon sequestration

Also known as carbon capture and storage, this technology involves the storage of carbon dioxide (CO2) that is a by-product of industrial processes through its injection into oil fields. It is not a form of renewable energy production, but it may be a way to significantly reduce the impact of fossil fuels whilst renewables are developed. The technology has been successfully pioneered in Norway but is still a relatively untried concept. The British Geological Survey estimate that potentially 755 billion tonnes of CO2 could be stored in the North Sea (Scotland's annual CO2 output is circa 50 million tonnes). The process also aids the recovery of oil and gas as it increases pressure in the oil field. The DTI estimate that as much as 2 billion additional barrels of oil could be recovered as a result of CO2 injection.^[3] However, although this process could reduce CO2 emissions from conventional power plants by as much as 80-90%, if combined with increased oil recovery the net savings in carbon emissions may be much less as the total volume of oil and gas used from that field would increase.^[5]

[edit] 'Clean coal' technology

Doosan Babcock Energy Limited (aka 'Mitsui Babcock') based in Renfrew (and elsewhere in the UK) have conducted research into the clean coal concept^[65] and recently secured a contract with Scottish and Southern Energy plc for the retrofit of a 500 MW power station at Ferrybridge in England. The installation of a 'supercritical clean coal boiler' could save up to 500,000 tonnes of carbon dioxide a year compared to current performance.^[66] The process has however been criticised^[67] and is at best a means of ameliorating carbon emissions.

[edit] Incineration

There is a successful waste-to-energy incineration plant at Lerwick in Shetland which burns 22,000 tonnes of waste every year and provides district heating to over 600 customers.^[68] Although such plants generate carbon emissions through the the combustion of the biological material and plastic wastes (which derive from fossil fuels), they also reduce the damage done to the atmosphere from the creation of methane in landfill sites. This is a much more damaging greenhouse gas than the carbon dioxide the burning process produces,^[5] although other systems which do not involve district heating may have a similar carbon footprint to straightforward landfill degradation.^[69]

[edit] Hydrogen

Although hydrogen offers significant potential as an alternative to hydrocarbons as a carrier of energy, neither hydrogen itself nor the associated fuel cell technologies are sources of energy in themselves. Nevertheless, the combination of renewable technologies and hydrogen is of considerable interest to those seeking alternatives to fossil fuels.^[70] There are a number of Scottish projects involved in this research, supported by the Scottish Hydrogen & Fuel Cell Association.^[71]

The PURE project on Unst in Shetland is a ground-breaking training and research centre which uses a combination of the ample supplies of wind power and fuel cells. Two 15 kW turbines are attached to a 'Hypod' fuel cell, which in turn provides power for heating systems, the creation of stored liquid hydrogen and an innovative fuel-cell driven car. The project is community-owned and part of the Unst Partnership, the community's development trust.^[72]

In the Western Isles a plan to enable a £10 million waste management plant into a hydrogen production facility was announced in June 2006. The Council have also agreed to purchase hydrogen-fuelled buses and hope the new plant, which will be constructed in partnership with the local Hydrogen Research Laboratory, will supply island filling stations and houses and the industrial park at Arnish.^[73]

ITI Scotland is a programme of intermediate technology institutes. It has attracted the Alterg project, a French company that is developing technology for the cost-effective storage of hydrogen.^[74][75]

A very different approach is proposed by BP in partnership with Scottish and Southern Energy for the creation of a hydrogen-based power station at Peterhead. The project will take natural gas extracted from the North Sea, crack the gas to produce hydrogen and carbon dioxide, and burn the hydrogen as the fuel source to create electricity in a 475MW power station. The CO2 will be returned to the Miller field reservoir more than 4 kilometers under the seabed in a process called carbon sequestration (see above). The scheme is expected to be in production by 2009 at a projected cost of $600 m. When completed, the plant will be the first industrial-scale, hydrogen power station in the world.^[6]

[edit] Nuclear power

Renewable energy as a concept generally excludes nuclear power^[76][77] although this stance has been challenged.^[78][79]

Unlike existing nuclear fission technology, fusion power offers the potential for signficant power production without the dangers inherent in fission plants. Conceivably a fusion plant could be considered 'renewable' as the hydrogen fuel source is vast. However the research costs are also enormous and no facilities exist in Scotland. European research is concentrated at the JET laboratory near Oxford and commercial applications are still twenty years or more away.^[80]

[edit] Local vs national concerns

A significant feature of Scotland's renewable potential is that the resources are largely distant from the main centres of population. This is by no means co-incidental. The power of wind, wave and tide on the north and west coasts and for hydro in the mountains makes for dramatic scenery, but sometimes harsh living conditions. One writer described the Hebrides as "the Isles on the Edge of the Sea where men are welcome - if they are hard in body and in spirit tenacious."^[81]

This happenstance of geography and climate has created various tensions. There is clearly a significant difference between a renewable energy production facility of modest size providing an island community with all its energy needs, and an industrial scale power station which is designed to export power to far distant urban locations. Thus, plans for one of the world's largest onshore windfarms on the Hebridean island of Lewis, have generated considerable debate.^[20] A related issue is the planned high-voltage Beauly-Denny power line which would bring electricity from renewable projects in the north and west to the cities of the south. The matter has gone to a public inquiry and has been described as a "battle that pitches environmentalists against conservationists and giant energy companies against aristocratic landowners and clan chiefs".^[82]

There is considerable support for community-scale energy projects.^[83] For example, Alex Salmond, leader of the Scottish National Party, has stated that "we can think big by delivering small" and aspires to have a "million Scottish households with access to their own or community renewable generation within ten years".^[32] The John Muir Trust has also stated that "the best renewable energy options around wild land are small-scale, sensitively sited and adjacent to the communities directly benefiting from them,"^[84] although even community-owned schemes can prove controversial.

A related issue is the position of Scotland within the United Kingdom. It has been alleged that UK transmission pricing structures are weighted against the development of renewables in Scotland,^[85][86][87] a debate which highlights the contrast between the sparsely populated north of Scotland and the highly urbanised south and east of England. Although the ecological footprints of Scotland and England are similar the relationship between this footprint and the biocapacities of the respective countries are not. Scotland's biocapacity (a measure of the biologically productive area) is 4.52 global hectares (gha) per head, some 15% less than the current ecological impact.^[88] In other words, with a 15% reduction in consumption, the Scots population could live within the productive capacity of the land to support them. However, the UK ecological footprint is more than three times the biocapacity, which is only 1.6 gha head, amongst the lowest in Europe.^[89][90] Thus, to achieve the same end in the UK context, consumption would have to be reduced by about 66%.

The developed world's economy is presently very dependent on inexpensive 'point-source' fossil fuels. Scotland, as a relatively sparsely populated country with significant renewable resources, is in a unique position to demonstrate how the transition to a low-carbon, widely distributed energy economy can be undertaken. A balance will need to be struck between supporting this transition and providing exports to the economies of densely populated regions in the Central Belt and elsewhere, as they seek their own solutions.The tension between local and national needs in the Scottish context may therefore also play out on the wider UK and European stage.

[edit] Promotion of renewables

The Scottish Renewables Forum is an important intermediary organisation for the industry, hosting the annual Green Energy Awards.

The Highlands and Islands Community Energy Company (HICEC) provides advice, grant funding and finance for renewable energy projects developed by community groups in the north and west of Scotland.

Areg is a public-private partnership created to identify and promote renewable energy opportunities for businesses in the north-east.^[91]

The Forestry Commission is active in promoting the biomass potential.

The Climate Change Business Delivery Group aims to act as a way for businesses to share best practice and address the climate change challenge.

Numerous universities are playing a role in supporting energy research under the Supergen programme, including fuel cell research at St Andrews, marine technologies at Edinburgh, distributed power systems at Strathclyde^[45] and biomass crops at the UHI Millennium Institute's Orkney College.^[92]

[edit] Summary of Scotland's resource potential

Technology	Capacity in 2006 (GW)	Potential Capacity (GW)	Potential Energy (TWh)
Onshore Wind	0.94	11.50	45.0
Offshore Wind	0	25.00	82.0
Wave	0.00027	14.00	45.7
Tidal stream	0	7.50	33.5
Hydro	1.34	1.63	5.52
Wood	0.012	0.45	1.8?
Biomass (non wood)		0.84	6.6
Biodiesel		0.14	1.0
Landfill gas	0.061	0.07	0.6
Geothermal		1.50?	7.6
Solar			5.8
Total	2.4	62.63	236.6

Table notes and sources:

Total capacity from all sources in 2006 was estimated at 10.3 GW^[4] and 9.8 GW.^[3] It is estimated by RSPB Scotland et al (February 2006)^[2] that electricity output would decline from the current total of 50 TWh per annum to about a third of this figure by 2020 due to decommissioning of existing non-renewable capacity if no new capacity was installed. In 2006 total energy demand was 177.8 TWh.^[93] Electricity makes up 20% of total energy use, but about 15 TWh are exported or lost in transmission.^[2]

All figures above are from RSPB Scotland et al (February 2006)^[2] except as otherwise identified below. The main source assumes grid capacity is available. Without this the potential drops significantly to circa 33 TWh.

Current renewable capacity source:^[8] From this document 'Biomass electricity' of 12 MW is entered above as 'Wood' and 'Energy from Waste' of 61 MW as 'Landfill gas'.

The tidal potential of the Pentland Firth alone is estimated elsewhere at over 10 GW.^[33]

Potential hydro production source: extrapolated from 2004 data in^[36]

Potential wood production source:^[44]

Potential geothermal energy source:^[58]

Potential biomass energy is also estimated at 13.5 TWh^[58]

Potential solar energy source:^[58]

Potential Energy: '?' indicates an unsourced estimate based on potential capacity. Conversely, geothermal potential capacity is estimated from potential output.

Micro generation (including solar) is estimated as having the potential of producing up to 40% of current electrical demand by 2050 i.e. circa 14 TWh^[47] The above figures assume 12% by 2020.

New data appears on a regular basis. Milestones in 2007:

Commissioning of the Braes of Doune wind farm in February took the UK renewables installed capacity up to 2GW.^[94]

[edit] See also

• World energy resources and consumption
• Mechanical biological treatment
• Oil phase-out in Sweden
• Renewable energy in the European Union
• Renewable energy development
• Biofuel
• Global warming
• Greenhouse effect
• Hydrogen economy
• Intergovernmental Panel on Climate Change
• Peak oil

[edit] Main references

• Monbiot, George (2006) Heat: How to Stop the Planet Burning. London. Allen Lane.
• RSPB Scotland, WWF Scotland and FOE Scotland (February 2006) The Power of Scotland:Cutting Carbon with Scotland's Renewable Energy. RSPB et al.
• Scottish Executive (2005) Choosing Our Future: Scotland's Sustainable Development Strategy. Edinburgh.
• Scottish Renewables Forum. Market and Planning Report (various).[12]
• The Role of Nuclear Power in a Low Carbon Economy. (2006) Sustainable Development Commission. London.
• Royal Society of Edinburgh (June 2006) Inquiry into Energy Issues for Scotland. Final Report. Edinburgh. RSE.

[edit] Citations and footnotes

[edit] External links

• Scottish Renewables Forum
• Scottish Sustainable Development Forum
• European Marine Energy Centre - EMEC
• PURE
• Use Wood Fuel