- Try to maintain a roughly similar middle-class lifestyle, with some compromises (eg less meat in the diet and less aviation usage). But still, people would be living in similar quality warm housing to today, with ample food, readily available personal transportation, hot water, electricity at the flick of a switch, etc).
- The transportation sector would be largely electrified (primarily via electric cars, but also via increased use of rail, electric scooters, etc).
- Heat pumps would be heavily used for heat provision.
- The electrification of transportation and the use of heat pumps means that electricity demand would roughly double over today's level
- Various forms of bio-energy (chiefly biogas and biochar) would be used to fill all the gaps.
- Energy demand is assumed to be much smoother than today, primarily achieved by charging electric cars at night, and using a lot of thermal storage in buildings, so that heating can primarily be done at night when electricity demand would otherwise be lower, and then allowed to dissipate to the rest of the building during the day.
- Relatively low levels of energy trade with the rest of the world are assumed (this isn't really necessary to make the zero-carbon part work, but I think reflects a general bias by environmentalists against trade).
Here is overall delivered energy in this scenario:
As you can see, this relies very heavily on offshore wind. In particularly, almost three quarters of electricity production is from offshore wind:
This reflects the facts that a) wind is the most mature of the renewable options, and b) Britain has an enormous wind resource, and is a pretty lousy place to put solar power, being too far north. The 195GW box in this next map is the area that would be required to be covered in wind farms to provide as much power as is called for. Obviously, it's a lot of wind turbines, but it's certainly a lot less than 100% of the potential resource.
The biggest issue I see with this set of choices is that, because the entirety of Britain can be nearly windless at times, a near-complete duplication of this generation capacity has to be maintained in the bio-electricity sector, and that will have very low utilization (and thus poor economics). The implications for land-use of so much bioenergy we'll have to look at when we go over that chapter.