Regular readers will be well aware of my long-standing scepticism as to the value of a policy of generous Feed-in Tariffs (FITs) to support small-scale solar PV installations. I see that my blog category on the topic of FITs now has no fewer than 10 posts (11 with this one), dating back to February 2008 – and that first entry included a letter sent to the Guardian in December 2007. So I’ve been documenting this fiasco for 4 years – so far.
DECC have launched yet another review of FITs. It seems like just yesterday I responded to their fast-track review. Don’t try and read this in DECC’s amazing non-scrolling spreadsheet (downloadable from their FIT fast-track consultation page) but I see I ended my answer to their question 2 (which mostly consisted of expressions of astonishment that they had no effective mechanism for controlling the cost of FITs) by saying:
“If the intention is to exclude investors altogether and encourage only those pursuing a low-carbon lifestyle or self-sufficiency, then the domestic PV tariff should be reduced by at least 50% immediately.”
which is only what they’ve gone and done!
Subsequent to sending off my response to the fast-track consultation back in May, I realised that the most efficient way of setting FIT rates would be by auction (it seems some people made this point in their responses back then). The latest consultation is another opportunity for me to make this point.
But there are even bigger (fitter?) fish to fry. Just in time (normally abbreviated to JIT, so maybe I can say “JIT for FIT policy…”!), the Royal Society held a two-day discussion meeting on solar power in mid-November. As you’d expect there was a lot of discussion of new whizzy technologies. But a couple of more prosaic points struck me:
- Solar power generation in the UK is limited by the available space, David MacKay emphasising this point in particular.
- New solar PV technologies – that might convert a greater proportion of sunlight into electricity – are finding it difficult to get to market. As costs are lowered for these technologies, “traditional” silicon-wafer based PV continues to build scale economies.
In other words, FIT policies and other government subsidies around the world are driving prices down for the wrong technology for Britain. We don’t want 10% efficient panels, we want to turn 30-40% of the energy in sunlight into electricity.
Now, if you have a roof of a limited size, then, once there are no subsidies and the cost of solar PV is competitive with other forms of energy, you’ll choose the most efficient technology that continues to yield cost savings compared to buying electricity. That is, you’ll consider panels of 10% efficiency, 15%, 20% and so on until the cost per additional kWh over the lifetime of the panel exceeds the value of the electricity generated.
But subsidies screw things up.
Specifically, in the UK FIT scheme, you’re limited by the banding to a certain size of installation. For example, the tariff for an installation of up to 4kW capacity is 21p/kWh. For 4-10kW it’s only 16.8p/kWh. So installations are typically of just under 4kW capacity. If your roof can accomodate a cheap 4kW panel there’s no incentive to instal a more efficient panel. Or even to use the whole roof. The UK’s solar resource is being squandered.
There are many ways to address the problem. You could devise all kinds of rules and regulations to ensure people used more efficient panels to drive down the costs of the best technologies.
One simple approach, though, might be to base the banding on installation area, not capacity. That is, the highest tariffs would be for installations that used just a few square metres. This would provide an incentive to squeeze as much energy out of the space as possible. It would also be more equitable as it would favour the owners of large roofs much less than does the present system. Most important, though, such a scheme would provide a market to help bring down the cost of the technologies we need for the future.
The present system ensures that all the available FIT income will go to owners of large roofs. Because more efficient panels cost more per Watt, the Government will keep lowering the tariff in response to a surge of installations of less efficient panels as their price comes down because of scale economies. The FIT will never be high enough to justify installations of more expensive, more efficient panels on smaller roofs.
Tariffs for installations starting at (say) just 5m^2 roof space (compared to around 25m^2 for typical panels in a 4kW installation today) would ensure there is a market for the more efficient panels.
The approach of FIT banding by installation area rather than capacity could be simply combined with auctions – that is, prospective PV generators would bid the lowest FIT they were prepared to accept for one of a quota of solar PV installations of a given area – up to 5m^2, up to 10m^2 and so on.