Tuesday 26 September 2023

If Only...

If only there were more days like yesterday: where Solar and Wind generation exceeded fossil fuels (for a short while).

The Gridwatch.co.uk graph for the day looks like this:


Sadly this is an exceedingly rare event. 

Both gas AND solar exceeded the output around 1pm. After that? Well, it's back to gas filling the void as the weak autumn afternoon sunshine peters out. 

The grey band of Nuclear seems to be consistently providing baseband throughout the day. There's hardly a day it's offline.

And this is where I looked at having an all-electric system on my boat which seems to be the latest fad at the boat shows: electric propulsion and induction hobs.

I looked into the energy consumption. Basically doing a few miles of travelling and then stopping and using electricity for heating and cooking. Hopefully the heat from the water-cooled electric motor can go into a calorifier to heat the water while cruising.

In summer the power generation was enough to exceed the supply of the energy budget. But in the winter I'd need at least to triple the amount of summer solar power to compensate for the shorter days and the weaker sunshine. 

To do that I'd have to devise some sort of solar sail that could be hoisted on a mast that could be raised and lowered easily. There's no way I could have a fixed solar array of sufficient size on the boat.

And that's the problem with solar at UK latitudes. At best we get around 12 hours of usable sunshine to generate power in the winter, but that's cut to around 4 hours in winter if it's not cloudy. There could be days where there is next to no sunshine at all and it's cloudy. It could go on for weeks. Yes, I know solar panels do generate power in cloudy weather, but it's a fraction of the energy provided by direct sunlight. 

So you end up in winter with a fraction of the time providing usable sunshine compared to summer and you have constant cloud, which then provides a fraction of the sunshine that could be available. 

If you are relying on solar, that's a problem. 

I wouldn't rely in a solely solar setup for a boat. I'd go for a hybrid solution, so you've always got the option of sparking up the generator to charge the batteries. 

Renewables: still not good enough to rely on.