The centre for alternative technology have brought out another Zero carbon Britain report. There is not the space to blog on the full report, but here some of the main points of interest as far as we are concerned.
Zero carbon Britain envisages a reduction in energy use from the current 1,750 TWh to around 665 TWh per year (60%). This is largely to be brought about by insulation and much more efficient use of energy (smart meters and smart demand as we cover in our book). Industry and domestic users switch to electricity and synthetic methane. Zero carbon Britain does not advocate a way of getting there but describes a number of approaches (such as TEQ’s or carbon taxes) with their pros and cons.
In my view. Gone is the previous Zero carbon Britain reports reliance on implausible numbers of house demolitions. However the report is too vague on how we really get such a huge reduction in energy use. The drivers for this will have to be very strong. Other than TEQ’s which is my preferred option (see our book for details in the Transition chapter), there are huge uncontrolled rises in energy prices due to crisis’s or taxes. A little more detail would have been good.
We will still need energy. Zero carbon Britain sees a totally renewable future with 770 TWh annual energy demand met by renewables (105TWh a year comes from heat pumps added onto the figure above).
|offshore wind||530||140 GW maximum power,
14,000 turbines rated 10 MW
|onshore wind||51|| 20 GW maximum power,
10,000 turbines rated 2 MW
|wave power||25||10 GW maximum power|
|tidal (range and stream)||42||20 GW maximum power|
|solar PV||58|| 75 GW maximum power,
covering 10-15% of UK roof area
|geothermal electricity||24||3 GW maximum power|
|hydropower||8||3 GW maximum power|
In addition they visualise another 25TWh/year of renewable heat from solar hot water and 15 of geothermal heat used to heat buildings and the 105TWh from heat pumps. On top of this Zero carbon Britain looks for another 274TWh of biomass energy this is used to power a few vehicles, run some industries (for example cement needs large amounts of heat), heat some buildings and act as an energy storage medium to balance renewable supply with user demand. This biomass is largely grown on land used for meat production, which is much reduced.
In my view. Much to commend here. If anything they are being conservative on the renewables, although as they point out if you added more you would end up with a surplus at some times of year and still end up with deficit at others. It does raise some interesting questions though. For example there are just under 4000 wind turbines of the size that disturb people onshore. Its difficult to see this doubling in number with increasing resistance. However, the slack could be made up by other renewables.
75GWp of PV seems on the low side. I just wonder what to do when PV cruises past 75GW? This is only 10-15% of the available roof space, although some of the other 85-90% is allocated to solar hot water. I calculate from the projected heat output there would be 16-17 million such systems, most of the houses in the UK would have them fitted. Of course my house has both and there would be a possibility of having both on many UK houses. My biggest gripe with this section is over heat pumps. Having looked into them for our book “No oil in the lamp” I’m not convinced they will work retrofitted into new buildings. The problem is most forms of renewable heat systems won’t either. Nor is a COP value of 2 any use. The minimum such value is 4. There is however some very interesting work on balancing out different renewables using 10 years of past weather data. 82% of the time using the Zero carbon Britain model the electricity supply is in surplus. The rest of the time they look to synthetic gas to balance out the deficit.
Zero carbon Britain (like our book) envisages almost all transport to be electrified. The amount of electricity needed for this is large but manageable. Dividing their figure for the electricity required in kWh by electric cars per person per year we get almost the same figure of about 1kWh per person per day. This assumes no range increase. They are negative about the hydrogen economy, as are we, but for different reasons.
In my view. The only questions I would raise is over supply of rare earths and the energy used to make the cars although they allow energy in their scenario for industry.
Zero carbon Britain looks to a much lower consumption of meat. I think this is right. I’m trying to cut the meat down in our family. They usefully indicate what the diet would look like in 2030.
Campaigning and what you can do
Very positively the report has some sections for individuals and campaigners on changing their own and other peoples lifestyles.
Despite my criticisms above I’m very positive. The modelling on balancing out renewables is particularly valuable. Its just a bit vague on how we are going to get there on demand reduction. But for anyone interested in the kind of areas this blog is, its a valuable resource.