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Renew your energy: January 2010 Archives

The wrong FIT?

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In April the government is to launch a Feed In Tariff for small renewables- the 'Clean Energy Cashback' scheme – and details of the tariff rates should emerge next week. Under it, electricity supply companies will offer guaranteed payments for electricity generated from renewable energy devices that consumers have installed their own homes, or to small projects installed by community organisation and the like, the limit being 5MW. See my earlier blog for details:

Eligible technologies include micro wind turbines, photovoltaic modules, micro hydro plants, and biomass-fired units. In the domestic sector, PV solar seems likely to dominate – micro wind is only really viable in a limited number of places and micro biomass units for electricity generation (usually micro CHP) are still relatively novel.

The Feed-In Tariff (FiT) that has been running for several years now in Germany has certainly helped get PV established, so maybe that will also happen here. The theory is that this guaranteed subsidy helps build the market for PV, so that prices begin to fall – and the FiT support can then be reduced. The German system has a built-in annual price 'degression' formula to take account of that. And it seems to work – PV prices have fallen and installed capacity has grown.

However, it has to be said that this has come at a cost: the supply companies pass on the FiT charges on to all electricity consumers. PV is expensive. But since the PV element the German FiT has so far been relatively small (most of the FiT has been used to support wind, which is cheaper) the overall cost of the FiT to consumers has been relatively small – initially 3–4% or so extra on average bills. However, with demand for PV increasing due to the FiT and the reduced cost of PV, there have been concerns about loading consumers up with the higher costs. That has already led to a cap on total PV capacity supported under the FiT in place in Spain. And the German government has now decided to reduce the FiT support rate for PV by15% to reduce the cost to consumers.

Initially, the German government was clearly convinced that PV was a major option for the future – as is widely accepted to be the case. It did of course have to balance the costs to consumers, the expected reduction in prices as the FIT helped PV move down its learning curve, and how much capacity was wanted, but it obviously felt that it was right to push PV ahead rapidly. Now, however, following a shift to the political right, it's being more cautious. That change was no doubt buttressed by claims by the German news magazine Spiegel that the additional costs for subsidizing new PV installations in 2009, based on initial industry estimates for new installations of around 700 MW, could be as high as €10bn over the course of the 20-year FiT programme. And also by the study published last year by RWI (Rheinisch-Westfaelisches Institut für Wirtschaftsforschung), which claimed the extra cost added to consumers bills was around 7.5% p.a., and calculated the total cost of PV to German electricity users could be more than €77 bn over a 25-year period. These estimates may be inflated: the German Institute for Economic Research (DIW) put the latter cost at €50 bn. But it did seem that a continuing rapid expansion of PV was going to put more cost on consumers.

Basically the problem is that, although they are falling under the FiT, PV costs are still high at present, much higher than for other renewables, and the rapid expansion of PV meant the cost to consumers was too high. A problem really of success! By contrast, near-market options like large wind turbines are much cheaper/kW and per kWh, and so FiT support for wind cost consumers less in total. And so wind has been the main focus, with the result being that the German FiT has helped support 25 GW of wind capacity, and only about 4 GW of PV.

The UK FiT

What does this mean for the UK? If FiT's aren't that good at supporting expensive options like PV without loading up consumers with high costs, arguably we've got it the wrong way around in our approach. FiTs should be used for the big cost-effective stuff. We are using it for the small expensive stuff.

It could be that, nevertheless, as the UK's 'Clean Energy Cashback' FiT gets going, customers who are willing and able to borrow money to install the equipment will push ahead, as happened in Germany. The guaranteed FiT income does make it easier to get loans from banks. And it's certainly better than the than the UK's dismal ROC/Renewables Obligation system. But what smaller expensive projects like PV really need is up-front capital grants. The UK tried that earlier with the PV grants system in the Low Carbon Building programme – but the level of demand for grants was such that it overwhelmed the relatively small scheme, and there were limits to how much more taxpayers money the government felt it could provide. Hence the interest in a FIT for PV and other small renewables – then its the consumers who pay.

The FIT may work well for some people. At present, for those with money, investing in PV solar will give a better return, via the FiT, than banks offer! But what about those without money? In the pre-budget report last December, the government said that 'although feed-in tariffs and the Renewable Heat Incentive will make payments over the life of installations, low-income households may still find it difficult to meet upfront costs'. It added that 'building on the experience of pilot projects for Pay as You Save financing and Warm Front,' it will consult 'on measures to help low-income households take advantage of clean energy cash-back'. That could help. And some community schemes may also prosper.

Even so, sadly, not much is expected on the UK FiT. At best, the government sees it as delivering just 2% of electricity by 2020. The Renewables Obligation (RO) is seen as the main way ahead, helping us to get about 30% from renewables, mostly wind, by 2020. So far, using the RO, plus a few capital grants, we've barely made it to 6%, with only tiny amounts of PV. And the RO has loaded up consumers with much higher prices per kW and kWh than under the German FiT system- even though the latter also included support for much more PV. Ofgem, the energy regulator, has reportedly estimated that the RO cost consumers £1 bn last year and a total of £4.4 bn so far. But it has only helped support 4 GW of wind generation capacity (some of which also benefited from grants), compared to the 25 GW installed under the FIT in Germany. So in general, in terms of capacity and costs, FITs are a much better option.

Whether that will prove true of the limited UK version for small projects remains to be seen. It will be interesting to see what the government comes up with next week in terms of tariff levels. Will PV get enough to move ahead seriously? And if so, what will that cost us?

Interest in using the scheme seems high. A YouGov survey for Friends of the Earth the Renewable Energy Association and the Cooperative Group found that 71% of homeowners said they would consider installing green energy systems if they were paid enough cash – and 64% of those asked thought that the government's plans were not ambitious enough. But what if it puts bills significantly? The poll showed that 70% of respondents said that they would be prepared to pay an extra 10p on their electricity bills each month (£1.20 annually), on top of the already proposed annual increase of £1.17, until 2013 when the scheme is due to be reviewed. So maybe there is an appetite for change.

Neil Crumpton, a member of the Bath-based Claverton Energy Group of energy experts and practitioners, and also Friends of the Earth Cymru's energy campaigner, has produced a draft zero-carbon, non-nuclear scenario to 2050 and beyond intended to initiate feedback and debate in the Claverton Energy Group. It aims to identify the low-carbon energy generating and supply infrastructure needed to build a resilient, demand-responsive UK energy system. It relies heavily on renewables, urban heat grids, possibly suburban hydrogen networks, and carbon capture and storage (CCS) during the four decades of transition.

It is very ambitious. Renewables would supply about 200TWh/y by 2020, scaling up to more than 1,100 TWh/y by 2050. Offshore windfarms, at least 10 miles from any coast occupying some 20,000 sq. km, would supply ~ 550 TWh/y, about half his estimated 2050 final energy demand. But the real innovation starts on the heat side, with much use of Combined Heat and Power plants and large heat pumps feeding industrial users and town/ city heat grids. Up to 15 GWe of industrial Combined Heat and Power (CHP) plants would supply industrial clusters, while 15 GWe or more of urban Combined Heat Pump and Power (CHP&P) schemes (typically 0.5–100 MW) would distribute reject heat from fast-response 'aero-derivative' gas turbines, and large heat pumps.

They would feed heat grids, with up to 5 GWe of 'initiator' CHP&P schemes, progressively linked up to form wider district and eventually town-wide and city-wide heat grids over the next 15–20 years. Large-scale heat pump installations would deliver renewable heat from air and ground- and from solar thermal and geothermal sources.

Even more innovatively, large thermal stores (accumulators), up to traditional gasometer-scale, would optimise the system. Peaking renewable electricity, particularly from marine technologies, would primarily be stored as heat at electricity 'regenerator' sites comprising a mix of technologies like molten salt stores and 10 GWe or more of steam turbines, electrolysers and hydrogen fuel cells and compressed air. Chemicals and fuel synthesis could also feature and connection to the heat grids would greatly aid conversion and regeneration efficiency and heat demand response.

Crumpton says 'such an energy storage and electricity regeneration capability would be a significant aid to delivering the UK's large but highly variable renewable energy resources, particularly wind energy, to consumers as and when demanded'.

Initially the energy input for the heat grids would be mostly from gas, but all the gas-fired industrial CHP and urban CHP&P capacity would be progressively converted to hydrogen, piped in from coal and biomass CCS gasifiers. There could also be a direct solar heat input to local heat stores, and possibly also some from geothermal sources. Low-pressure hydrogen might also be supplied to the 9.5 million sub-urban homes via the existing (upgraded) gas network to power 10–30 GWe of mCHP boilers (possibly fuel cell) and domestic heat pumps.

All large emitters would be fitted with Carbon Capture by 2025. CCS fitted gasifiers co-fired with 15+% biomass or imported solar synthetic fuels would then provide 'carbon-negative' baseload to the extent climate protection policy required. The 10 GW of CCGTs already consented would operate until about 2040, then be retained for occasional duty during prolonged winter anti-cyclones.

There would also be HVDC links to Europe, including Norwegian hydro and pumped storage schemes, which would help optimise the system to high marine renewable variability, and open the option of delivering net imports of around 10% of final energy from Saharan wind and concentrated solar power schemes.

The complete system, with molten salt heat stores at regeneration sites, would comprise some 50 GW of firm electricity generation, plus peaking plant, suburban mCHP, and inter-connectors. He says the system's firm generation and storage capacity would be designed to supply 'smart' demand even during a deep winter anti-cyclone lasting days. And he says that 'Depending on the availability of sustainable bio-sources and transport sector emissions, the UK could be net zero carbon by 2040'.

It is of course all very speculative, although the use of large heat pumps is not novel- The Hague has a 2.7 MW (ammonia) seawater community heating scheme and Stockholm has a total of 420 MW (multiple 30 MW units) of heat / cold pumps feeding its district heating / cooling grid. Crumpton says 'The large heat pumps would harness heat from sources which 11 million urban domestic heat pumps could not do, including large solar thermal arrays and geothermal'.

Using coal still might worry some environmentalists, but there would be CCS and he says it would be used in minimal amounts by 2050. Generating and piping hydrogen is also a novel idea – but there are now some pilot schemes in the UK. And piping heat is much more common – on the continent.

Installing that, and the rest of the system, would though involve a lot of new infrastructure, but he claims that 'strategic siting the gasifiers would combine locations with good transport access for coal and biomass (dock-sides, railheads, collieries), together with hydrogen pipeline routes to CHP schemes, and CO2 pipelines to geological storage sites under the North Sea or Liverpool Bay'. And similarly 'regeneration schemes should be sited adjacent to industrial clusters, refineries, and existing chemical sites with hydrogen, CO2 and heat grid pipeline access'. In addition, 'coastal locations with direct HVDC connection from marine renewables would minimise need for new cross-country transmission lines'.

So disruption would be reduced. Nevertheless, building the heat grids (polypropylene pipes) would involve some short-term local disruption to pavements and roads during the pipe/conduit laying. But he says it would 'provide low-carbon energy infrastructure for the children of today and future generations'.

The draft scenario is outlined in more detail in the current issue of Renew (183):

The debate over how to deal with the variable energy output from wind turbines continues to rumble on. Some say that, when wind availability is low, there will be a need for extensive back up from conventional plant to maintain grid reliability. However, this backup may already exist: we have a lot of gas-fired capacity, much of which is used regularly, on a daily basis, to balance variations in conventional supply and in demand. Balancing wind variations means this will just have to be used a few times more often each year, adding a small cost penalty and undermining the carbon savings from using wind very slightly. But some say we will need much more that that. A report from Parsons Brinckerhoff (PB) claims that "the current mix of generating plant will be unable to ensure reliable electricity supply with significantly more than 10 GW of wind capacity. For larger wind capacity to be managed successfully, up to 10 GW of fast response generating plant or controllable load will be needed to balance the electricity system".

"Controllable load" includes the idea of having interactive smart grids which can switch off some devices when demand is high or renewable supplies are low.

However even if that option is available, some say that, with more wind on the grid, to meet peak demand, we will still need more backup plants than we have. By contrast, wind energy consultant David Milborrow claims we have enough, and that some fossil-fired plants can actually be retired when wind capacity is added. That depends on the "capacity credit" of wind – how much of the wind plant capacity can be relied on statistically to meet peak demand. Milborrow puts the capacity credit of wind at around 30% with low levels wind on the grid, falling to 15% at high levels (at say 40% wind on the grid). That indicates how much fossil plant can be replaced.

PB see it very differently: "A high penetration of intermittent renewable generation drastically reduces the baseload regime, undermining the economic case for more-efficient plant types with lower carbon emissions."

Milborow admits that balancing wind variations has the effect of reducing the load factor for thermal plant, but says that this only costs ~£2.5/MWh at 20% wind, or ~ £6/MWh at 40%. PB will have none of this: "Very high early penetration of wind generation is likely to have adverse effects on the rest of the generating fleet, undermining the benefits of an increased contribution of renewable electricity."

PB also seems to slam the door on a possible way out, importing power from continental Europe, the wider footprint then helping to balance variations across a much larger geographical area. It says: "Electricity interconnection with mainland Europe would offer some fast-response capability, but would be unlikely to offer predictable support. Without additional fast-response balancing facilities, significant numbers of UK electricity consumers could regularly experience interruptions or a drop in voltage."

Addressing the interconnector issue, among others, TradeWind, a European project funded under the EU's Intelligent Energy-Europe Programme, looked at the maximal and reliable integration of wind power in Trans European power markets. It used European wind power time series to calculate the effect of geographical aggregation on wind's contribution to generation. And it looked ahead to a very large future programme, with its 2020 Medium scenario involving 200 GW – a 12% pan-EU wind power penetration. It found that aggregating wind energy production from multiple countries strongly increased the capacity credit.

It also noted that "load" and wind energy are positively correlated – improving the capacity factor – the degree to which energy output matches energy demand. For the 2020 Medium scenario the countries studied showed an average annual wind capacity factor of 23–25 %, rising to 30–40 %, when considering power production during the 100 highest peak load situations – in almost all the cases studied, it was found that wind generation produces more than average during peak load hours.

Given that "the effect of windpower aggregation is the strongest when wind power is shared between all European countries", cross-EU grid links were seen as vital. If no wind energy is exchanged between European countries, the capacity credit in Europe is 8%, which corresponds to only 16 GW for the assumed 200 GW installed capacity. But since "the wider the countries are geographically distributed, the higher the resulting capacity credit" if Europe is calculated as one wind energy production system and wind energy is distributed across many countries according to individual load profiles, the capacity credit almost doubles to a level of 14%, which it says corresponds to approximately 27 GW of firm power in the system.

Clearly then, with very large wind programmes you do get diminishing returns and need more backup, but it seems that can be offset to some extent by wider interconnectivity – the supergrid idea, linking up renewables sources across the EU.

That is already underway. The UK's National Grid has agreed with its Norwegian counterpart Statnett to draw up proposals for a £1 bn grid-interconnector grid link-up, to be funded on a 50:50 basis, which could help solve the problem of winds intermittency, given that Norwegian hydro could act as back-up for the UK, in return for electricity from the UK on windy days. As yet no UK landfall site has been indicated, but it could include connection nodes along the route with spurs taking power from offshore wind farms and become the backbone of a new North Sea "supergrid": the UK and eight other North West EU countries have now agreed to explore interconnector links across the North sea and Irish sea. National Grid said: "Greater interconnection with Europe will be an important tool to help us balance the system with large quantities of variable wind generation in the UK."

In recent years, "science" has increasingly been asked to provide guidance on issues such as climate change. However, there are limits both to what science can do and to its influence. For example, although there has been much talk of relying on "evidence-based research" as a guide to action, in reality, decisions are often made on the basis of other information, or views, or influences. In some cases science is just used to justify decisions already taken. Scientists are very much "on tap, not on top".

Science is not, however, entirely impotent. Climate change has been an example of where science has created a new agenda. But that involves some responsibilities. Given the cultural and ideological relativism that seems to be the norm these days, it is perhaps not surprising that some have latched on to the climate change issue as a new fundamentalism. Here at last was a really powerful determinism, providing a clear "scientifically backed" case, with added moral an ethical imperatives for the sort of technical, social and political prescriptions preferred by, among others, radical "greens". It has, for some, gone beyond science and on to a belief. Hence the bitterness at any hint of climate-change denial, or any scepticism about humans being responsible for it.

Trying to sustain this degree of absolute certainly, and denying rival views, is bad for science, which needs open, pluralistic, debate and challenges to keep it as objective as possible. That is not to say that all views have equal weight. There are processes for weighing the strength of arguments and analysis, for testing conjectures, checking data. The "scientific method" may not be perfect – it's a human system after all – but it is arguably the best that we have come up so far for trying to make sense of the material world.

As far as climate issues are concerned, what it has suggested is that, with about 90% certainty, climate change is underway and is mostly due to human actions. That still leaves room for other views – and other explanations. Less palatably, it also leaves room for bitter disagreements and invective. Some climate sceptics attribute base and deceitful motives to some climate scientists – and vice versa. "They" are, variously, in the pay of evil oil companies/or devious eco-fascists/leftists, and so on.

The recent (Nov 2009) affair involving e-mail leak at the UEA played well to the sceptics – and even to the full-on climate-change deniers. It even worried fundamentalist climate-change believers – some of the scientific priesthood looked like it might be corrupt! The reality seems to be that some poorly worded descriptions of quite normal data-processing activities were made public: with many data sets, it is necessary to subtract spurious trends to see what is actually the main process at work. That can of course sometimes be controversial: but we rely on scientists to make it clear what they are doing and why, to their peers, so that their analysis can be tested and, if necessary, challenged. This is not best done by leaked e-mail extracts and invective from climate sceptics. After all they are often, to put it mildly, prone to deceitful use of data. Pots calling Kettles black, springs to mind. Even so, this episode does remind us of the need for proper scientific rigor – on all sides.

Other leaks concerned the peer-review and publishing process, which is how analyses and conclusions are meant to be tested and checked. A degree of collusion seems to be implied – in part, evidently, to keep deviant views out. This is much less palatable. The risk is that we end up with a self-serving, self-selected elite, who review each others papers and funding bids. I am sure most climate scientists are not like this; what motivates them is finding the truth. But in the face of ever increasing, often very illiberal and incoherent attacks by climate deniers and sceptics, it is understandable that some scientists may resort to defensive measures – by "keeping nutters out". That is tragic if it corrupts the debate, which should be as open as possible. But both sides have to play by reasonable standards, to have a proper debate. Some climate deniers and sceptics do not. So it is understandable that some climate scientists feel that they have to fight back, and for example publicly disparage views they see as dubious. But, although there is a need for more "public understanding of science", it is demeaning for scientists to get too involved in brawls with lobby groups, some of whose mission seems to be an ideological one. It might be better to leave that to green pressure groups and the wider political process, and focus instead on cleaning up your own act, so that there are no reasons for adverse publicity.

All that said, in an imperfect world, maybe we have to accept the need for virulent sceptical oversight of all things, including science. So the climate sceptics may have done us all a favour by putting the scientists' work under tighter scrutiny. But if cynicism sets in across the board, then we are not much further forward, and we may even be losing ground to those who say all that matters is ''belief". Faith may be a wonderful thing, and vision too – science is not the whole story. As the UEA's Mike Hume noted in a recent Guardian article, science can't help you decide about values or ideology. But science, properly done, can help when you are trying to decide politically about practical changes in material reality.


2010 looks like being the year when offshore wind power takes off globally in a major way. Europe is currently the global leader – during 2008, 366 MW of new offshore wind capacity was installed, bringing the cumulative total in EU waters to 1471 MW. And the UK is for once at the front of the pack- having overtaken Denmark last year with over 600 MW installed. Longer term, the European Wind Energy Association says cumulative offshore wind capacity in Europe may reach 40 GW by 2020 and 150 GW in 2030.

So far, the largest project planned is the 1 GW London Array in the Thames estuary, with work expected to start early next year, and completion of the first 630 MW part scheduled for 2012. But shortly details will emerge of the nine winners in the UK's 'Round Three' offshore wind project competition, which could see wind farms of up to 5 or even 10GW being established off the east coast.

Initially, in the first phase of offshore wind deployment, on-land wind turbine designs were in effect 'marinized' for offshore use, and located relatively near to shore. But now new design concepts are emerging specifically for the challenging offshore environment. They are larger: several 10 MW offshore turbines are currently under development, including Clipper wind's Britannia, and the novel vertical-axis 'Nova'. And they involve new ways of installing them further out to sea: seven radical new designs for offshore wind turbine foundations have been identified by the Carbon Trust, in a global competition involving over 100 candidates from engineering companies around the world. Selected designs include floating turbines anchored to the seabed, and spider-like tripod structures, along with more conventional monopiles – steel tubes driven into the sea-bed.

The overall aim of the Carbon Trust programme is to accelerate the construction of offshore wind farms by reducing construction costs and overcoming key engineering challenges of going further out to sea, in deep water up to 100 miles out, in depths of up to 60 metres, or maybe more. Up to three final winners will have their designs built and installed in large-scale demonstration projects in 2010–2012 with funding from a consortium led by the Carbon Trust.

The new wind turbine designs

The NOVA is perhaps the most dramatic new turbine design. It is a giant 120-metre tall 10 MW, V-shaped vertical-axis turbine, funded as part of the Energy Technology Institute's £20 m wind support programme. The NOVA consortium includes groups from Cranfield, Sheffield and Strathclyde Universities. Prof. Frergal Brennan from Cranfield told Cleantech (Vol. 4 Issue 4) that 'offshore vertical-axis wind turbines offer the potential for a break through in offshore wind energy availability and reduced life cycle costs due to their design characteristics of few moving parts and the sitting of the generator at the base level potentially allowing large-scale direct drive. Their relatively low centre of gravity and overturning movements make the turbines highly suitable for offshore installation'.

Meanwhile, VertAx Wind Ltd is working with SeRoc, Giffords and others on their own 10 MW H-shaped vertical axis offshore turbine. VertAx say it will be ready for operation in about 5 years. But Clipper wind's more conventional propeller type 10MW Britannia should be ready by 2011.

Perhaps the most novel design is the ETI-supported Blue H 'Deepwater' turbine project, which is focused on the design and feasibility of a 5 MW floating offshore wind turbine, for use in up to 300m of water. A steel prototype is being tested in the Mediterranean, but the ETI funded project will focus on concrete construction to cut costs. The development consortium is led by Blue H Technologies of the Netherlands with BAE Systems, the Centre for Environment, Fisheries and Aquaculture, EDF Energy, Romax and SLP Energy.

According to a study by the Carbon Trust, the UK will need to build at least 29 GW of offshore wind by 2020. The UK Energy Research Centre says that 'Whilst this represents a challenge similar in scale to developing North Sea oil and gas, it is seen as technically feasible'. But UKERC is currently looking at the economic prospects. It notes that 'during 2000 to 2004, offshore wind power costs were relatively stable with typical CapEx ranging from c. £1 m to £1.5 m/MW. But, in the last 5 years costs have risen dramatically, doubling from approx £1.6 m to £3.2 m/MW. The main drivers for this are supply chain constraints for components (e.g. wind turbine generators) and services (e.g. installation), and to a lesser extent, fluctuations in the Euro/Sterling exchange rates and commodity prices'.

Looking forward, it says recent estimates of the short to medium term cost outlook are that, in the absence of extreme movements in macro economic conditions and/or the onshore wind power market, offshore wind CapEx is not expected to alter dramatically over the next five years. In fact, it says, the industry consensus is for a slight rise in the next two years, followed by a slight fall out to 2014/2015.

The UK is of course not alone in developing offshore wind. In addition to projects in Denmark, the Netherlands, Norway, Sweden, Belgium, France, Germany, and elsewhere in Europe, in 2009 China installed its first 3-MW 90 metre diameter 'Sinovel' offshore wind turbine, the first unit of a 100 MW Shanghai Donghai Bridge demonstration project. In parallel there are said to be some 37 offshore wind projects under development in the USA.

Although costs are higher offshore, load factors are also higher, and, potential impacts on sea mammals aside, there are fewer environmental impact issues to contend with than with on-land location. Moreover, as wind projects are sited further and further out to sea, there will be fewer conflicts with in-shore/coastal fishing and navigation interests. With the North Sea possibly able to offer 200 GW or more of generation capacity ultimately, and large resources also existing elsewhere in the world, offshore wind seems to have a bright future.

For a roundup see: