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Tag Archives: renewable heat

Labour’s green gas push

By Dave Elliott

‘Turning certain rubbish materials and farm and food waste into various types of biogas – ‘green gas’ – holds the potential to cut costs, radically reduce pollution, and decrease our reliance on imports. Crucially, using more green gas could make a real impact on the decarbonisation of heat without the need to overhaul our national gas pipeline and heat delivery infrastructure and without significant technical barriers’. So say Labour MPs Lisa Nandy and Caroline Flint in the Green Gas book published by the Parliamentary Labour Party Energy and Climate Change Committee.

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ETI on energy saving in buildings

By Dave Elliott

The UK Energy Technologies Institute’s report by Jeff Douglas on Decarbonising Heat for UK Homes notes that ~20% of CO2 emissions are from domestic heating, but says insulation/upgrades won’t cut that enough: ‘the scope for cost effectively reducing the energy demand of existing buildings to the great extent required to meet emissions targets is limited as comprehensive insulation and improvement measures are expensive and intrusive. A several hundred billion pound investment in demand reduction for the entire building stock might deliver less than half of the emissions abatement needed. The most cost effective solutions therefore involve the decarbonisation of the energy supply combined with efficiency improvements that are selectively rather than universally applied, as part of a composite package’.

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UK energy policy – grinding to a halt?

By Dave Elliott

At a meeting of the House of Commons Liaison Committee, which brings together the chairs of select committees, PM David Cameron in effect provided an overview of his take on key aspects of UK energy policy. It was quite revealing, with justifications being offered for the extensive cut-backs in support for most low-carbon projects, in order ‘to deliver low carbon at the lowest cost’. Very little seems to have survived unscathed. (more…)

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Plenty of renewables – and they can be balanced

By Dave Elliott

Is there enough renewable energy to meet global needs and can the use of variable sources be effectively balanced?  Recent reports say yes on both counts. In terms of the total resource, a GIS-based study of land/sea use/availability has put the total 2070 global potential for renewable electricity at up to 3,810 EJ, led by solar PV, with about a third of the PV being on buildings. The total estimated resource was roughly in line with most other global renewable studies, like that from the IPCC, and well above likely total global electricity demand, put at around 400 EJ: www.sciencedirect.com/science/article/pii/S0959378015000072 (more…)

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DECC Reviews Renewables

By Dave Elliott

In its 2014 review of renewable energy policy, part of its Electricity Market Reform deployment exercise, the UK Department of Energy and Climate Change outlined how it saw each key option developing: http://www.gov.uk/government/news/ensuring-value-for-money-and-maintaining-investment-in-renewable-energy
There have certainly been some changes since its 2011 Renewable Roadmap, which selected eight technologies as likely to be key to meeting the UK’s 2020 renewables targets. www.decc.gov.uk/en/content/cms/meeting_energy/renewable_ener/re_roadmap/re_roadmap.aspx
PV solar was not amongst the selected eight. But now it’s a front runner. In its new report DECC says, ‘We consider solar PV now to be an established technology in the UK,’ and with 2.7GW or more in place that’s clearly true. And they add ‘Solar is anticipated to be the first large-scale renewable technology to be able to deploy without financial support at some point in the mid-to-late 2020s’. Didn’t it do well! Despite the cuts in Feed In Tariffs. DECCs main concern now seem to be that PV, especially solar farms, will expand too fast! They note that ‘Solar PV is a technology which can be deployed quickly even at large scale’. But they are worried about the costs and eco-impacts of large ground mounted projects and would prefer Building Integrated schemes, large and small. On costs, they accept that these are falling (which is why take-up has grown) and will continue to fall (in part due to the take-up), but they say ‘because the UK is a small part of the global market, it is likely that these cost reductions will largely occur independently of what the UK does’. And they have sought to limit the cost pass-through to consumers, most notably by entirely cutting Renewables Obligation (RO) support for large projects. Otherwise they say they might reach 5GW by 2020! Nevertheless they still talk of an overall possible 10GW of PV by 2020 and perhaps even 20 GW.

Wind power did feature strongly in the 2011 DECC review, offshore especially. Now, despite being the cheapest of the main new renewables, on land-wind has fallen out of favour in some circles (e.g.due to vociferous campaigning and some local opposition), although, as DECC says, ‘current installed capacity in the UK is 7.3GW, with a further 1.5GW under construction’ and ‘there is also a large potential pipeline of UK projects with 5.4 GW having received planning consent and a further 6.5GW currently in the planning system. This means we are well on our way to reaching our ambition for 11-13GW of onshore wind by 2020’. But by contrast offshore wind is seen the biggie: ‘Offshore wind is the most scalable of the renewable technologies, and it is the renewable technology that has the most potential to make a significant contribution to decarbonisation goals, if required. There is significant long-term potential for cost reduction and it is at an early stage of deployment – DECC’s central estimate is a 25-30% reduction in central costs by 2030, which could be higher depending on the level of deployment between now and then. The UK is the market leader for offshore wind, with the biggest pipeline to 2020, and deployment in the UK is therefore a key driver of cost reduction to 2020’. DECC had earlier said up to 39GW was possible by 2030. But that depended on the market. www.gov.uk/government/consultations/transition-from-the-renewables-obligation-to-contracts-for-difference

Wave and tidal stream also featured in DECC’s 2011 Renewable Energy Roadmap, which suggested that there could be 200-300 MW of marine capacity by 2020. That was much less than the 1-2 GW forecast in the Government’s Marine Energy Action Plan 2010, or even the 1.3GW by 2020 UK figure in the EU Renewable Energy Action Plan. And although the UK is still in the lead in this area, the new DECC Review reduces its expectations further: ‘Wave and tidal stream technologies are still at the demonstration stage and are not currently competing in the mainstream market. There are currently around c.10MW of wave and tidal stream capacity deployed in sea trial around the UK – more than the rest of the world combined. We anticipate that by 2020, wave and tidal stream could reach 100-150MW in the UK alone. This deployment could then increase quickly beyond 2020 to reach GW-levels in the late 2020s-early 2030s’.

Unlike heat pumps (still strongly backed), geothermal wasn’t in DECCs 2011 key options list, but a 2012 SKM study claimed that it could supply 20% of UK electricity from around 9.5GW of capacity. The new DECC review however relies on a 2013 Atkins report on deep geothermal power which suggested a possible best case potential of up to 3-4% of current average UK electricity demand. So it’s still seen as something of an outsider option, although worth backing.

By contrast, DECC is still very enamored of biomass, including EfW combustion, advanced gasification/pyrolysis, biomass CHP and AD from farm and other wastes. There are limits though, mainly related to land use constraints and concerns about the sustainability of importing biomass pellets for large biomass conversion plants. I’ll be looking at that in my next but one post.

The new DECC renewables review is just about electricity supplies, so it doesn’t look at solar or biomass heat (both being pushed quite hard by the Renewable Heat Incentive), or biofuels (on which progress is less spectacular). But arguably it does add up to a package might help the UK meet it 2020 15% renewable energy target. However, with the various cuts and uncertainties about the effects of the new Contracts for a Difference support system, that is not certain: DECC has just imposed a £205m p.a. cap on renewable CfD allocations up to 2020 which may constrain new offshore wind and large PV solar projects seriously. https://www.gov.uk/government/news/over-200-million-boost-for-renewables I will be looking at that in my next post. And beyond 2020 there are no renewables targets, with, under current policies, the continued expansion of renewables likely to be constrained by the commitment to nuclear and maybe shale gas CCS. But policies can change and with renewables costs falling, they may break through further and accelerate more, so there is still all to play for.

If so, what about grid balancing? DECC has confirmed that it will be seeking 53GW of contracted capacity for the new ‘capacity market’ for 2018/19, to help deal with supply shortfalls due to demand peaks, variable renewable inputs and plant or grid failures. For the moment much of this will involve existing gas plants that might otherwise be closed, given the increased output from renewables, but will be needed occasionally when that output is low. However any facility that can provide grid balancing services can apply to the capacity auction process in December, including storage and demand management. Contracted capacity will get a cash incentive for being available. DECC says it will add £2p to average annual consumer bills over the period 2014-30. https://www.gov.uk/government/news/britains-energy-security-strategy-now-fully-in-place

So what next? Given its excellent renewable resources, clearly in principle the UK could, if it wanted to, at least match the German ambition of getting 80% of electricity from renewables by 2050. Assuming that is Scotland, which has most of the resources, is still part of the UK! Carboncommentary.com noted that about 15 GW of 2020 renewables will be in Scotland or in Scottish waters. Only about 18 GW will be in England and Wales. So it said Independence would mean around 40% of total UK renewables capacity would disappear, but only 10% of UK electricity consumption. www.carboncommentary.com/2014/04/

DECC sees it differently, arguing that Scotland’s small population would not be able to sustain the cost of its large renewables capacity without the RO income from the rest of the UK – or a £189 p.a increase on Scottish consumer’s bills. But in reality wouldn’t the UK have to buy in, and continue to support, Scottish green power to meet it renewable targets? DECC also sees the nuclear issue differently, and, with the European Commission currently looking at the UK’s proposals for funding the EdF Hinkley project, Westminster has evidently warned the (anti nuclear) Scottish government that any negative representation it made to Brussels on this would be viewed as a ‘hostile act’. www.heraldscotland.com/politics/wider-political-news/minister-sought-to-dissuade-msp-from-role-in-eu-inquiry-inquiry.23914772
Clearly the independence referendum is going to be a lively affair!

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Sustainable heating and cooling for buildings

by Dave Elliott

 ‘40% of Europe’s energy use and a third of the greenhouse gas emissions can be attributed to buildings and much of this relates to heating and cooling. For example in the UK, 38% of all CO2 emissions are related to space heating. These emissions can be avoided or significantly reduced through a combination of holistic design, integrated renewable energy and high efficiency.’  So says a report on Sustainable Heating and Cooling of Buildings from Leonardo Energy, the European Copper Institute’s think tank, offering a good analysis of the options for reducing buildings’ energy consumption  and carbon emissions. (more…)

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CfD – early winners

By Dave Elliott

The UK’s new  Contracts for a Difference system will replace the Renewables Obligation fully from 2017, but before then some green energy projects will be supported under it. 16 have been earmarked for consideration for this early support under the Final Investment Decision (FID) ‘Enabling for Renewables’ process.

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Renewables: observing the future

by Dave Elliott

In its business leader column on August 25th The Observer, said “If there is a body of opinion that states that wind farms and energy efficiency can fill the looming energy gap, then it is small and deeply unrepresentative”. www.theguardian.com/business/2013/aug/25/anger-fracking-cant-manage-without-gas

Germany is aiming to get at least 80% of its electricity from renewables by 2050, with overall energy demand cut by 50%, so the Observer seems to have it wildly wrong, certainly long term.  And in fact, far from being marginal, around 50 countries are already getting more than 60% of their electricity from renewables in the form of hydro, some of them near 100%. http://k.lenz.name/LB/?p=6525. Longer term, dozens of studies claim that renewables could supply 100% of the worlds electricity in many countries by around 2050. http://www.mng.org.uk/gh/scenarios.htm. That is what Denmark and New Zealand are aiming for and many others see renewable as their main future energy option- with China leading the way.

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Energy storage technologies

by Dave Elliott

There are many energy storage options which can be used balance grid systems so as to compensate for the variable output from some renewables. They include existing and newly emerging electro-chemical and electro-mechanical systems (batteries, pumped storage and compressed air storage), as well as a range of thermal and hydrogen based systems www.electricitystorage.org/ 

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Green Heat 1

I have often been less than impressed by reports from the Royal Academy of Engineering (RAE) , which usually seems to take a conservative line on energy issues, but their new report on heating for buildings seems overall very well done, although with lapses. It makes the sensible point that we need to deal with the building envelop first, but also notes that most of the houses that will be lived in by 2050 have already been built, so we must look to remedial measures. It also notes that ‘Manchester isn’t Leipzig’, and looks at patterns of heating need and perceptions of comfort. It assumes we are talking about well insulated buildings, and familiar levels of comfort, and it reviews the energy supply options for supporting that.

It sets the scene by pointing out that ‘If space heating could be decoupled from water heating it would change the selection criteria for heating appliances and boilers. There would no longer be a need for the heating system (as opposed to the hot water system) to be on standby during summer months or to be capable of operating at a sufficiently high temperature to prevent Legionella developing in water systems. All domestic heating is currently thought of as low-grade heat requirement, but there is a case for distinguishing space heating as low grade and hot water as medium grade. A policy for heat should separate these two different uses’.

It looks at heat pumps as a possibility, but is not too convinced. ‘While the general reduction in carbon intensity of grid electricity makes the use of electric heating (direct or via a heat pump) more attractive, peak heat loads tend to coincide with peak electricity loads. There is, therefore, a significant likelihood of heating demand being met by high carbon electricity generation brought onto the system to meet peak loads over and above the capacity of low carbon generators’.

It goes on ‘Air source heat pumps have been rising in popularity for new build in the UK, but this is partly an effect of the way in which electrical energy is treated in the regulations that makes CO2 targets more lenient than for gas systems.’ While it admits that ‘Air source heat pumps integrate well with well insulated dwellings, if properly sized and installed,’ and it suggests that ‘micro-CHP complements and could balance some of the properties of heat pumps’, it also notes that ‘several reports discuss inadequacies of the application or system engineering in heat pump installations. It is clear that heat pumps are not forgiving if installed inappropriately.’

By contrast, it’s much happier will larger-scale communal system. ‘Communal air source heat pumps are an interesting area of development with some new configurations of systems coming to market. Central systems may be more efficient and are likely to offer much greater energy storage than do systems designed for individual household’.

It adds ‘Larger district systems, incorporating a CHP facility and providing heating are significantly more efficient than domestic level installations. This is because waste heat can be used in district heating after it has generated an element of electricity. Such district heat is therefore always of significantly lower CO2 emissions than any heat only production utilising the same fuel’. And that, it seems, includes domestic scale heat pumps.

The RAE does seem to been moving towards community- scaled system across the board. However, it is less happy with renewables. Although it sees some potential for bioenergy e.g for CHP/District Heating , it is not very impressed with solar, and overall treats renewables as problematic in terms of grid power supply, reverting to the traditional RAE line on the problems of intermittency and the delights of nuclear: ‘During the summer months, most of the night-time load could be provided by nuclear power with renewables providing additional power during the day’, while in winter ‘we would need sufficient renewables to guarantee 40GW during the evening peak. As wind, tides and the sun are intermittent, that would require significantly higher installed capacity of renewables or thermal back-up capacity, much of which would be unused for long periods in the summer’ making renewables uneconomic.

Nevertheless, it does look at smart grid /load management options which might change the situation radically, helping to deal with intermittency. A bit grudging, but at least there is now some recognition that a new interactive supply and demand system might be viable. It’s taken decades to get the community CHP/DH message across to the traditionalist engineers, so maybe it’s too early for idea of smart dynamic grids to have got through! And it may take even longer for them to give up on ‘baseload’ nuclear, which they still see as essential, rather than as getting in the way of a more interactive flexible system based on renewables ( which is the view emerging from Germany) .

However, as far as CHP/DH in concerned, the RAE is now full of praise. It says that ‘CHP plants, biomass combustion, and heat pumps are more efficient, reliable and cheaper at scales larger than a single dwelling. The costs of large scale heat pump installations per kW are a quarter of that for domestic-scale installations.’ It adds that ‘it is more efficient to use the available skills for fewer large systems than for many individual units’, and that, since energy storage will be needed ‘district heating systems have another important benefit – the mass of water in the underground pipes provides a heat store that evens out daily peaks and troughs in demand. This can be supplemented by hot water tanks to increase energy storage’. And taking it one step further, it points out that ‘well insulated hot water tanks or underground inter-seasonal thermal stores will be simpler to provide on a community basis given the small (and reducing) size of most UK homes’.

Some sense last! And DECC seem to be taking notice, in their new Heat strategy- see my next Blog.

‘Heat: degrees of comfort?’ Royal Academy of Engineering www.raeng.org.uk/heat

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