I've a 100% renewable electricity tariff. Would installing solar PV on my home be good or bad for the environment?

Ok, so I have recently shifted to a 100% renewable tariff from https://bulb.co.uk. It’s great, cheaper than my old tariff as well.

On my list for this year was to install some solar PV and a battery but then I started thinking.

If my energy is already delivered from renewable sources, why do I need to generate my own renewable power?

Of course, it might benefit me financially, but is there any real need from an environmental perspective?

Then I started thinking of reasons why having my own install might actually be bad for the environment. For example, energy generation (like most things) benefits from economy of scale. Presumably, it is more efficient to generate 5GW of power than 5MW in terms of the materials and energy needed. Therefore it would make more sense for my electricity supplier to simply add more capacity rather than for me to generate my own.

Also, I was planning to have battery storage. Making batteries is bad for the environment. Presumably, my supplier is not making a battery pack for every 5MW of power they generate.

The only environmental reason for adding my own solar PV system that I can think of is that I do not have to incur transmission losses. I really have no idea how much this is but this document from the National Grid puts them at between 6.7% and 9.7%.

As a consumer, I have absolutely no idea how to navigate these issues. I certainly don’t want to spend thousands of pounds thinking that I am doing something good for the environment and actually end up making things worse.

Can anyone help?

Some extra details of my situation. I live on a boat (picture below) .Our heating is electric and biomass (5Kw log burner) so no fossil fuel boiler etc :sunglasses: On the downside, our electricity consumption is absolutely massive during the winter months. I was planning to spend around 10k on a solar PV install to help with the bills but also because I thought it would be the right thing to do from an environmental perspective. The alternative would be to spend that 10k on upgrading the insulation, perhaps adding external insulation to the upstairs walls and roof.

Google Photos


Most experts would probably suggest tackling all insulation opportunities to reduce demand and then create a heating system to best meet that demand. Have you considered solar thermal? There’s an interesting new podcast on this topic which might offer some options for you - although I appreciate that space might eb tight for you. Have a listen: https://www.buzzsprout.com/509671/2445728-renewable-heating-solar-thermal Back to the PV question, I don’t have the technical experience to comment but maybe speak to bulb to get their view or jump on twitter to get wider views.

Thanks @Locky. Yes, I was thinking that insulation would be a better bet for me than solar PV. However, I’m still interested in the broader question of whether it is good or bad for the environment for anyone who is on a 100% renewables tariff to install solar PV.

I’m no expert but I think you fall in to the camp of doing far more than a lot of people so don’t beat yourself up too much. I’d do the insulation first and then work out a way of generating income / energy in the least damaging way. I’ve PV installed, it is a pleasant financial payment quarterly. Maybe to counterbalance any guilt you might have go to Good for the Energy, which is 100% generated renewable but where you will pay 20% more. Your conscience should be clear at that point.

Thanks for the support @Alandawson66. I’m not actually trying to clear my conscience here though. I didn’t mean to give the impression that this was a moral question. I am actually just interested in whether it will have a positive or negative impact on the environment to install solar PV if you are already on a renewables tariff. The crux of the issue seems to be whether your supplier will respond to your increased demand by installing new capacity or not. I’m still not sure what the answer is here.