Richard Black, former BBC Environment Correspondent and now director of the Energy and Climate Intelligence Unit is asking questions
of Owen Paterson, In particular, he asks, "Where is the evidence that the UK will experience blackouts unless emission targets are scrapped?"
None of the major players in the field, he says, not DECC, the National Grid nor Ofgem, believe the lights are about to go out, although it is true that the amount of "headroom" between peak demand and peak supply has been falling.
The Coalition government, he adds, has just opened its first capacity market auction a process designed explicitly to ensure that the "lights stay on" in an era of increasing renewable and nuclear generation.
The capacity market can award contracts for 15 years; nuclear stations such as Hinkley C are set to generate for 35 years with price support. So what evidence is there to support the "lights going out" thesis?
As one might expect from a former BBC employee, however, Black is missing the point. Paterson is not talking about the short-term. He is looking at the longer term, to 2050 and the mandatory 80 percent emissions cut.
The basis of the estimations is the official DECC 2050 scenarios
(in particular, pathway Alpha: pp 17-18) which state that, in order to meet the 2050 emission targets, domestic heating and much of the private transport fleet must be electrified. At the same time, electricity generation must be totally decarbonised. No CO2 producing equipment can be permitted.
Most 2050 scenarios posit a doubling of electricity demand, even after energy efficiency measures. The gives a projected winter peak demand of 120GW based on current figures. There is no point looking at total electricity production when it comes to preventing blackouts on cold, dark, winter nights, what matters is available capacity.
To deliver with certainty, a winter peak of 120GW, we must expect, on the basis of the current structure of the electricity industry, a capacity requirement of anything from 160-200GW. The exact figure will depend on the proportion of wind and solar in the mix.
The government has not been explicit about the generation mix for 2050 in fact, it has avoided giving any details. But looking at a realistic requirement, with a high level of renewables (wind and solar), there will be actually be a need for about 200GW installed capacity which must all be "carbon-free" generation. This seems to be confirmed in the graph for pathway Alpha, which suggests an average daily load of about 100GW - double that to get a capacity figure.
The government expects there will be a heavy reliance on nuclear. Figures of 40-80GW have been mentioned (although one scenario of 146GW is posited). There is no explicit target for wind, but we can assume up to 60GW capacity. From hydro, interconnectors and "others", we might get 20GW.
Then there is about 20GW installed solar power capacity planned. That gives us about 180GW, so we would be looking at a balance of up to 20GW CCS-abated gas and coal-fired generation which will only come on line from about 2030 onwards.
Now looking at the real world, with the current nuclear programme, and the time it has taken just to get approval for Hinkley C, together with the spiralling costs (£24bn at last estimate), there can be no confidence that even the lower estimate of 40GW can be reached. We would be very fortunate to get 20GW.
Wind has struggled to reach just over 10GW installed capacity by 2013 and the chances of another 50GW being installed in the next 37 years are remote. Solar could make 20GW or even more, but since it cannot produce electricity in the dark, when peak requirements occur, the capacity is of no value for planning purposes, in dealing with expected peaks.
We assume a shortfall on nuclear - let's say we manage 20GW more than we have at the moment. There will most likely be a shortfall on wind, allowing an installed capacity of an incredibly generous 50GW.
We can allow the hydro, interconnector and "others" at 20GW. Solar will not be available at peak times, which will be during winter evenings. And, unless there are technological and economic breakthroughs, we cannot assume that any CCS-abated capacity will be available. At the moment, its availability is theoretical the government is relying on technology that does not yet exist in commercially available form.
On a cold, windless night, when the peaks are most likely to occur, there may be no wind. This leaves 20GW from nuclear, 20GW from hydro, interconnectors and others, and in the absence of CCS-abated gas and coal, nothing much else. That is 40GW against a 120GW requirement. Even if wind was fully available, that is just 90GW leaving a 30GW gap.
There are, however, all sorts of mitigation strategies, including the balancing reserve and demand management, and storage, but much of that such as smart meters and the smart grid - lie in the future, with no firm dates for implementation, much less completion.
On what we know, therefore, massive electricity shortfalls are inevitable, if the 2050 80 percent emissions target is kept. Turning this round, the government must offer us firm, funded proposals for meeting the capacity requirements against solid capacity estimates, needed to meet its "decarbonisation" scenario.
At the moment, on costs - against EU and IEA estimates of £1.3tn - all it can offer is this:
Providing a comprehensive estimate of the costs of decarbonisation out to 2050 is very challenging. First, it is impossible to predict accurately how fuel and technology costs will develop over such a long period. Costs will necessarily depend on the assumptions on fuel prices, technology development and the paths taken by other countries. And in some sectors the technological solutions required to allow the necessary emissions reductions are not yet known. Second, many of the wider impacts of the move to a low carbon economy are very difficult to quantify, for example those on security of supply, the wider environment and people's behaviours.
If the government cannot do better than that, then any challenge about when whether the lights will go out is misplaced. Instead, the government should be asked what the evidence is that the lights will stay on. On current form, it has none.