Thinking about micro generation (wind, solar, hydro)

  • 8 August 2020
  • 5 replies

We're looking at a new-build project and obviously the house will be well insulated and consume as little energy as possible.

The site has the potential for solar PV and thermal, small-scale hydro and wind.

Ignoring an ROI analysis of each technology, and given that we'll be spending some money on grid-supplied electricty anyway.

If I focus on climate impact rather than my electricity spendaspend over time, should I support a 100% green-energy provider like PurePlanet instead of generating my own power?

Any kit I buy to generate power will have its own carbon footprint including manufacture and shipping.

I assume that the greenest of green energy generators are those that operate at massive scale - monster wind turbine versus a handful of solar panels on my roof.

Has anyone done that kind of comparison?  If so, I'd welcome any pointers on bringing myself up to speed on how to evaluate this kind of back-to-back test based on CO2 rather than cash.

5 replies

I follow your logic @martindell, but I’ve got no idea of the answer. I look forward to hearing someone’s informed answer...

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Wow i would love to have the option to build such a place. Given the money (which at the end of the day is proberly the biggest factor) i would build something off grid. Solar and wind for electric rain capture and filtering for water, reed beds for sewage and waste water the list is almost endless. Short term there is a carbon impact but long term the benefits outway the loss.

Intuitively I feel there ought to be a benefit of cooperating with others via the grid. When one home is becalmed on a misty day, others might have sunshine or wind. Factor in the economies of scale of larger installations and the net global cost ought to be lower compared everyone going it alone. 

However, the independence of not relying on others might be appealing come the apocalypse...

Thanks all, I can see the pros and cons on both sides. I had hoped that it would have been studied / compared somewhere by someone better qualified than me.

Personally, I'd much prefer to simply pay for green energy (like we're doing now) rather than invest in equipment and play the ROI game.

Aside from the thrill of being self-sufficient, I would not be thrilled to maintain my own power generation equipment (wind and hydro especially).

Unless there's a compelling CO2 reduction of micro v large scale generation, I can think of better / greener uses of capital rather than buying equipment.


I suggest that your priority for spending (capital and carbon outlay) should be on minimising your demand for energy.  As in your post, consume as little as possible.  If you can achieve this then your own domestic need for generation should be relatively small and deliverable with a moderate solar array, which would not cost a great deal to install and would require negligible maintenance.  Addition of a battery now or in the future would allow you to time shift, generate during the day and consume in the evening.

For advice you could try a local energy coop (e.g. operates in Bath area) or energy advice service (e.g. national, or which operates in Bath / Bristol area).