2.6 kWh/d per person. The Baltic and Mediterranean coastlines have no
tidal resource worth talking of.

Solar photovoltaics and thermal panels on roofs

Most places are sunnier than the UK, so solar panels would deliver more
power in continental Europe. 10 m2 of roof-mounted photovoltaic panels
would deliver about 7 kWh/d in all places south of the UK. Similarly, 2 m2
of water-heating panels could deliver on average 3.6 kWh/d of low-grade
thermal heat. (I don’t see much point in suggesting having more than 2 m2
per person of water-heating panels, since this capacity would already be
enough to saturate typical demand for hot water.)

What else?

The total so far is 9 + 6.4 + 2 + 2.6 + 7 + 3.6 = 30.6 kWh/d per person. The
only resources not mentioned so far are geothermal power, and large-scale
solar farming (with mirrors, panels, or biomass).

Geothermal power might work, but it’s still in the research stages. I
suggest treating it like fusion power: a good investment, but not to be
relied on.

So what about solar farming? We could imagine using 5% of Europe
(450 m2 per person) for solar photovoltaic farms like the Bavarian one in
figure 6.7 (which has a power density of 5 W/m2). This would deliver an
average power of

5 W/m2 × 450 m2 = 54 kWh/d per person.

Solar PV farming would, therefore, add up to something substantial. The
main problem with photovoltaic panels is their cost. Getting power during
the winter is also a concern!

Energy crops? Plants capture only 0.5 W/m2 (figure 6.11). Given that
Europe needs to feed itself, the non-food energy contribution from plants
in Europe can never be enormous. Yes, there will be some oil-seed rape
here and some forestry there, but I don’t imagine that the total non-food
contribution of plants could be more than 12 kWh/d per person.

The bottom line

Let’s be realistic. Just like Britain, Europe can’t live on its own renewables. So
if the aim is to get off fossil fuels, Europe needs nuclear power, or solar
power in other people’s deserts (as discussed on p179), or both.

Figure 30.2. A solar water heater providing hot water for a family in Michigan. The system’s pump is powered by the small photovoltaic panel on the left.