Category Archives: Renew your energy

Renewables in France – good targets, slow progress

By Dave Elliott

Although progress has been relatively slow, France has a quite ambitious energy policy, with nuclear to be cut back by around 25%, by 2025, so that it supplies a maximum of 50% of power, and renewables accelerating to supply 32% of energy by 2030 and double their share of electricity to 40% by the same year. Last year, according to BNEF data, France invested $5bn in Clean Energy, up 15% on 2016.

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Renewables in the EU and UK – the state of play

By Dave Elliott

The European Union is in the midst of resetting its longer-term targets for renewables, given the expectation that it will more or less meet its overall target of getting 20% of its total primary energy from renewable by 2020, with 11 countries already achieving or even exceeding the national targets set by the EU. For example, by 2016, Sweden had got to around 54%, 5% over its target, although some others have been doing less well: by 2016 the UK had only got to around 9%, against the actually quite low 15% national renewable energy target that had been agreed with the EU. But most of the laggards may just about reach their national targets by 2020 or soon after, hopefully even the UK. For the next stage, the European Commission initially proposed a somewhat unambitious overall EU target of 27% of primary energy by 2030, with individual national targets to be left to each country to decide.

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Jacobson’s new 100% renewables model aims to rebut critics

By Dave Elliott

Mark Jacobson and his team at Stanford University got some flack for their 100% global renewable energy study last year. It said 139 countries around the world could obtain 100% of their energy from wind, water and solar (WWS) sources by 2050. It had been based on their 2015 study that examined the ability of 48 US states to meet all their energy needs stably from these renewables. Some said their approach was flawed, and, for example, relied too heavily on energy storage solutions and on adding turbines to existing hydroelectric dams to get extra power – see here, for example.

In response, Jacobson and colleagues at Stanford, the University of California, Berkeley, and Aalborg University in Denmark, have now produced a new study focusing on 20 global regions encompassing the 139 countries, with supply and demand matching modelled for a range of storage/backup options over the period 2050-54.

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Supporting Renewables: FiTs not tenders?

By Dave Elliott

More and more national governments are transitioning from guaranteed price feed-in tariff models for supporting renewables to competitive tendering/contract auction schemes, justified in the belief that this will reduce costs. That’s the EU view, and tenders have also been backed by the International Renewable Energy Agency.  However, the German Energy Watch Group say this is a mistake: FiTs have been very successful and widely adopted, whereas there are big disadvantages with tenders, their main effect being that less capacity is installed, with smaller projects being excluded and competition actually being reduced. (more…)

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Renewable subsidies – and jobs

By Dave Elliott

A report from the Council of European Energy Regulators Status Review of Renewable Support Schemes in Europe puts the weighted average subsidy paid to renewable generators in EU 26 in 2015 as €110 /MWh. The maximum was €184/MWh in the Czech Republic and the minimum €16.2/MWh in Norway, while the UK came in at €75/MWh.

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Development aid and renewables: from aid to trade?

By Dave Elliott

Over the years, a lot of support has been provided for renewable energy projects in Africa, most recently under the UN Sustainable Energy for All programme, with the EU taking something of a lead. However, a shift in emphasis from development aid to economic partnership and trade is emerging, with private sector investment, local economic development and local enterprise seen as central, for example via Germany’s new ‘Compact with Africa’ initiative, the so-called Marshall Plan for Africa.

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Can nuclear be used to balance renewables?

By Dave Elliott

Nuclear plants are designed to run flat out, in part to recoup their large construction costs. Their output can be varied a bit, but this entails thermal stresses and potential safety issues with the build up of active xenon gas that is released when fission reactions are reduced. It needs time to decay. That limits how often and how quickly the plant can be ramped down and then back up so as to match changes in energy demand (“load following”) and the varying output of renewables. So basically nuclear plants are inflexible. Do they have any role for balancing variable renewables?  (more…)

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Rotatiload! Synchronous inertia and frequency stability

By Dave Elliott

Power engineers worry that, as more renewables are added to the grid, replacing old coal, gas and nuclear plants, we will loose lock-step AC synchronous system stability, since the latter had large heavy rotating turbo-generators which provided system inertia against frequency perturbations. The big plants’ rotational inertia acts as a buffer to grid frequency changes, and to varying supply and inductive loads. However, PV solar has no rotational inertia, and wind turbines not much, though direct drive machines can provide some. With more renewables on the grid it will become more of an issue: https://arxiv.org/pdf/1312.6435.pdf

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Firm power parity metric

By Dave Elliott

A paper from Imperial College proposes a new conceptual framework for understanding competition in electricity markets that include variable input but marginal cost renewables. Noting that one of the primary drivers for consumers to switch from grid-supplied electricity to self-generated electricity (e.g. home roof-top PV with batteries) is cost savings, the researchers constructed a model that forecasts when going-it-alone ‘grid defection’ by consumers may become widespread. In reality, few domestic consumers in the UK are likely to want to go entirely off grid. At least not for some time. Grid links are   needed and useful for backup, e.g. for when there has not been enough sunshine for a while and consumers’ batteries are discharged, and also to sell any surplus power they can generate, beyond what they can store. However, the grid defection analysis is still a useful conceptual exercise, not least since it gives us some idea of the cost of balancing/backing up variable renewables. And, in time, some users may want to try the off grid option. (more…)

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The cost of power: moving beyond LCOE

By Dave Elliott

How much does energy cost? LCOEs -Levelised Costs of Energy – are widely used as a comparative measure. They give an estimate for the cost of energy generation from specific plants, but do this by averaging out the investment and running costs over the plant’s lifetime and comparing that with the value of the electricity generated. However, the costs and earnings can and do vary over time and are hard to predict. LCOEs also omit any associated grid balancing/backup costs. So they have big shortcomings. Can we do better?

Certainly there are many weaknesses in the LCOE approach. Finance costs will depend on interest rates and inflation both of which can change over time, sometimes dramatically. So may fuel and labour costs. Energy output may also vary for many reasons and in the case of renewables will vary with the weather. In that case, use is usually made of ‘capacity factors’ to reflect average likely delivered outputs, but in reality these variations are dealt with by balancing capacity and services, the cost of which, arguably, should be added to the cost of generation.

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