Green, ethical, energy issues in the news

pile-o-stone

Martyn1981 wrote: »

Thanks for the chat, it's been interesting.

Agreed, and hopefully it was interesting to others and hasn't taken the thread too much off-topic.

One last observation. In Europe, 50% of biogas product comes from energy crops such as maize which produce a higher energy yield but their cultivation also causes soil erosion and has resulted in a rise in food prices for consumers.

If the fields are instead left to lie fallow, or even better are allowed to return to the woodland they used to be before being cleared for crops, the biomass would absorb more CO2 due to longer lifespan (i.e. no harvesting) and when they die, they can sequester CO2 into the earth (i.e. this is where coal and oil come from eventually) and also turned into furniture/building products in the case of trees.

Growing crops, harvesting and burning them is not carbon neutral, though it is less carbon intensive than burning !!!!!!, though trees and plants are carbon negative when left unburned.

NigeWick

pile-o-stone wrote: »

I know that it's generating next to nothing for me in winter and that even in summer, it would not allow me to be off grid, even with a battery.

Hmm, it's winter now and my 4kW system was powering the house, had heated water in the immersion and was shoving 1.2kW to the grid at 11:00 when I went to the allotment this morning.

I realise that the grid may be needed at times for shower, cooker or whatever but having solar plus battery will make it an awful lot less. If everybody had solar and battery backup, there would be much less need for more large scale generation and wind & solar with battery backup could cope easily. There'd also be no need for nuclear, gas & coal generation.

On to EV's:- How often would one need to completely charge the car from completely depleted? 1kWh will get me at least a mile even in winter with the heating on. My September to December FiT was £110 and I suspect that will be close to the amount that my system pushed to the grid. In the summer it would be a lot more. I honestly believe that with 13kWh of backup I would need very little electricity from the grid even in mid winter. Then if I can obtain a water recycling shower.....

NigeWick

michaels wrote: »

So what mix would may sense?

Home generated solar + battery backup and large scale renewables with battery backup for electricity. Super insulated buildings with Ecotricity's gas from grass for the small amount of heating required.

I actually believe we could produce so much renewable electricity that it could even cope with heating using heat pumps.

All it takes to get sorted is the political will, like Norway and their electric vehicle policies.

NigeWick

pile-o-stone wrote: »

It's important that those of us who are able to do so, do everything we can to reduce consumption, increase generation and help promote cleaner energy.

I agree completely.

I have put some money into a company that is producing small scale solar for people in Africa. It costs say £10 to buy lamp oil for a month. The solar lighting (from battery) costs £7 per month so that leaves people with £3 per month to invest in something else. The numbers are approximate but not far off.

NigeWick

Martyn1981 wrote: »

Have to say I disagree with you on this. It's just a matter of planning.

Yep, it's like planning a journey in an EV that has a limited range. Instead of doing 280 miles with one stop for a drink, sarnies and comfort break, I have two longer comfort breaks while the car sucks up renewable electricity from a rapid charger. I have two flasks so that my coffee doesn't get cold after the first stop. And yes, I had the two flasks before I got the EV.....

NigeWick

pile-o-stone wrote: »

I'd love to see RE replace everything, but I just don't see how it can, especially if we see a huge increase in demand from electric transport. Not in my lifetime anyway.

Charge vehicles off peak to balance the grid using smart chargers and V2G. Then we need to consider Transport as a Service reducing vehicles by up to 80%.

You must be very old because it could be done in 10-15 years.;)

Martyn1981

pile-o-stone wrote: »

Growing crops, harvesting and burning them is not carbon neutral, though it is less carbon intensive than burning !!!!!!, though trees and plants are carbon negative when left unburned.

Actually, unburnt trees aren't carbon negative, they are carbon neutral as eventually they will die and rot. The bio-mass industry just does the process faster.

Regarding bio-gas, have a read of Ecotricity's plans, they believe their process will actually enrich en the land by growing break crops, the bio-gas comes from grass crops, so is carbon neutral, apart from any emissions in harvesting and transport.

pile-o-stone

NigeWick wrote: »

Hmm, it's winter now and my 4kW system was powering the house, had heated water in the immersion and was shoving 1.2kW to the grid at 11:00 when I went to the allotment this morning.

I realise that the grid may be needed at times for shower, cooker or whatever but having solar plus battery will make it an awful lot less. If everybody had solar and battery backup, there would be much less need for more large scale generation and wind & solar with battery backup could cope easily. There'd also be no need for nuclear, gas & coal generation.

On to EV's:- How often would one need to completely charge the car from completely depleted? 1kWh will get me at least a mile even in winter with the heating on. My September to December FiT was £110 and I suspect that will be close to the amount that my system pushed to the grid. In the summer it would be a lot more. I honestly believe that with 13kWh of backup I would need very little electricity from the grid even in mid winter. Then if I can obtain a water recycling shower.....

That sounds amazing. My long-term ambition is to get where you are right now, but our roof orientation isn't great (E/W) for winter generation. The sun is shining and I'm generating 107w on the east 1.8kw array and 160w on the E/W 4kw array. With 267w, I'm not going to be able to go off-grid just yet.

pile-o-stone

Martyn1981 wrote: »

Actually, unburnt trees aren't carbon negative, they are carbon neutral as eventually they will die and rot. The bio-mass industry just does the process faster.

Regarding bio-gas, have a read of Ecotricity's plans, they believe their process will actually enrich en the land by growing break crops, the bio-gas comes from grass crops, so is carbon neutral, apart from any emissions in harvesting and transport.

The trees don't all rot down completely, or we'd have no coal. I'm not against bio gas, I just don't think it's as clean as other renewables and that if possible, they should have priority.

zeupater

pile-o-stone wrote: »

That sounds amazing. My long-term ambition is to get where you are right now, but our roof orientation isn't great (E/W) for winter generation. The sun is shining and I'm generating 107w on the east 1.8kw array and 160w on the E/W 4kw array. With 267w, I'm not going to be able to go off-grid just yet.

Hi

If the sun's currently shining on your 2kWp of west facing panels and the whole 4kWp array is only generating 160W, it sounds like you either have shade or a configuration problem ... is your E/W array inverter dual MPPT? ..

Our 4kWp array is closer to W than SW & it's been running the house baseload, providing ~3kW.t of heat, and still exporting around 75% of generation to the grid ... even when we've been using the kettle as well we've still been exporting! ...

Having said that, we're currently having a sharp shower (it's actually bucketing down!) & it's turned quite dull outside, but the PV is still generating 121W ... this is exactly where a home battery system would come in handy, all those banked electrons would be heating the house whilst this cloud passes over and there'd still be plenty left to provide heat until bedtime & power the house until early morning ...

HTH
Z