overall cost of installing Solar panels

[DonkeyApple]

Tobermory said:

I'm not so sure that local solar is so much worse than commercial as the equipment is pretty similar (the efficiency of the panels is similar) and commercial solar has to be manufactured and shipped etc.

For sure local solar is much worse than commercial wind or nuclear, no question.

Yes, I do see your point. If we get to a stage where the grid is as renewable as it can be then yes there would be no benefit in local solar and it could be potentially harmful. I'm just not sure we are anywhere close to that yet (the current UK grid mix produces around 200g CO2 per kWh of electricity) and so there is a window to make it work, and for sure there is a geeky fun element in it too.

For the record if there was a scheme whereby you could invest in additional commercial wind power or nuclear and get a 'dividend' similar to these savings then that would be a much better arrangement, but I'm not sure this exists.

Edited by Tobermory on Sunday 30th October 22:48

Yup. Solar, whether retail or commercial has the issue in the temperate U.K. that it's generation is not well aligned to usage but wind has a similar issue. But, centralised production will be much smarter than millions of small, private set ups as you can imagine.

I agree 100% with you that it would make much more sense to invest in commercial renewable generation than to become our own inefficient producer.

Rather than sticking a whole load of landfill stuff on our roofs and then having to pay for our own control system and have the whole fiasco of it producing the most when we typically need it the least, not being able to efficiently store it, having days when we basically need to bin the excess and other days when it's not enough, investing in the same capacity a bit like a big solar farm allotment where solar generation is optimised, set up as efficient as possible, like maintenance and where every electron generated has a known value would be much better.

However, setting up a scheme such as that would reveal the financial reality and that's arguably why it's not been done.

But this is why investing in the blue chip, dividend businesses that not only pay good dividends but have no choice but to work towards being as close to 100% renewable as possible is probably a better option until PV becomes more efficient and cheaper as well as energy storage becoming more efficient and cheaper.

For me, as I just can't work out where the yield is on becoming my own power generator or energy trader and can't get the justification for the enormous capex requirement to stack up, I'd prefer to invest the funds into the efficient producers.

For example, if I have £10k that I want to allocate to helping offset by utility costs and also want it to be carbon efficient then I'd look at this sort of investment:

£10k worth of SSE.L. It would cost me no more than £10 in broker fees to invest and because it's not a capex based investment, at any time I can take my money back. The value of that £10k may fluctuate but unlike capex it's not on a fixed, guaranteed trend to negative where it becomes worth zero but has a cost of disposal. In reality, over time the value of that £10k instead of trending to zero and below will increase. There's next to no carbon footprint to the investment either. In this case the stock yields 5% so from the outset you're earning a utility bill offset of £500/annum while retaining your original £10k.

Unless someone has the perfect roof angle and pitch, the perfect personal energy usage that maps solar generation well then in very many cases, investing in the U.K. blue chip utilities is typically going to deliver better as well as safer returns while being carbon neutral.

Its hugely tempting to be one's own power station. For me, the enormous temptation is to become an energy trader. Arbitrage trading and risk management has been my livelihood and it's tremendously appealing to sit there accumulating cheap, unwanted electricity into storage and then selling it to desperate peak buyers but that doesn't work either because the massive arbitrage only exists precisely because we can't actually store electricity efficiently. It's the entire nub of the issue we face.

The closest that I've got to is utilising the battery of an EV to compensate for the huge inefficiency of using an EV with a massive battery for those anomalous journeys when day to day you only actually need a tiny battery.

I find the whole area fascinating but do feel that there is an enormous obscurity on the numbers both fiscally and environmentally. I just don't see how it can be more environmental and I'm adamant the financials don't add up.

Projects such as yours are genuinely interesting and I hope you find the time to publish the data as the more of that there is from individuals heading down this path the greater the clarity will be.

[anonymous-user]

DonkeyApple said:

Tobermory said:

Stuff

Thanks, that's very interesting.

I'll definitely report back in due course

[Biggus thingus]

Previous said:

Biggus thingus said:

Just taken the plunge and had a 14no panel(4.2 Kw) system fitted either side of east/west facing detached garage

Invertor and 5.2 KwH battery also in garage

All done and dusted for £8 and half K

App to monitor gubbins only works on Apple so Mrs Thingus is looking after that side of things but we're generating, despite shocking weather since it was installed on wednesday

That sounds good. Which part of the country are you in?

Just outside Leeds

Firm that installed from near Northampton...Renewafuel

[Jambo85]

A few mentions of 15p/kWh for export - where are people getting this from?

One thing that is working well with the removal of FITs and basically making any export worthless, is that it is even more of an incentive for people to shift their demand where possible. A battery/EV is the extreme option, but more simply sticking the washing machine on in the middle of the day rather than at 7pm makes a big difference to the grid if done by millions.

Yes the same can and will be achieved via the grid with a smart meter and time of use pricing!

[rustyuk]

Jambo85 said:

A few mentions of 15p/kWh for export - where are people getting this from?

One thing that is working well with the removal of FITs and basically making any export worthless, is that it is even more of an incentive for people to shift their demand where possible. A battery/EV is the extreme option, but more simply sticking the washing machine on in the middle of the day rather than at 7pm makes a big difference to the grid if done by millions.

Yes the same can and will be achieved via the grid with a smart meter and time of use pricing!

Octopus are offering 15p/kWh

[dmsims]

rustyuk said:

Octopus are offering 15p/kWh

But not with Go(faster)

[DonkeyApple]

Jambo85 said:

A few mentions of 15p/kWh for export - where are people getting this from?

One thing that is working well with the removal of FITs and basically making any export worthless, is that it is even more of an incentive for people to shift their demand where possible. A battery/EV is the extreme option, but more simply sticking the washing machine on in the middle of the day rather than at 7pm makes a big difference to the grid if done by millions.

Yes the same can and will be achieved via the grid with a smart meter and time of use pricing!

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

[dmsims]

DonkeyApple said:

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

No you can't

[irc]

dmsims said:

DonkeyApple said:

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

No you can't

Possibly you can. Rarely.

"Store electricity at times of the day when the Agile prices are super low or even negative (on December 8 2018 Agile dropped to -2.31p per kWh). Then export from your battery when energy on the grid is most in demand, and most expensive. "

And the downside?

"Agile Octopus includes Price Cap Protect, which ensures you'll never pay more than 100p / kWh for your electricity, "

"you can't be on both Outgoing Octopus AND Octopus Go, our electricity consumption tariff designed for electric vehicle drivers – but any other consumption tariff is fine."

https://octopus.energy/blog/outgoing/

Presumably when this happens generation is tight. So Octopus buy your electricty at 15p and sell it for more.

But as I said won't happen often. Also is your calculations don't forget losses involved in charging your battery. 5Kwh in does not give you 5Kwh out.

Edited by irc on Monday 31st October 11:23

Edited by irc on Monday 31st October 11:24

[Jambo85]

irc said:

dmsims said:

DonkeyApple said:

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

No you can't

Possibly you can. Rarely.

"Store electricity at times of the day when the Agile prices are super low or even negative (on December 8 2018 Agile dropped to -2.31p per kWh). Then export from your battery when energy on the grid is most in demand, and most expensive. "

And the downside?

"Agile Octopus includes Price Cap Protect, which ensures you'll never pay more than 100p / kWh for your electricity, "

"you can't be on both Outgoing Octopus AND Octopus Go, our electricity consumption tariff designed for electric vehicle drivers – but any other consumption tariff is fine."

https://octopus.energy/blog/outgoing/

Presumably when this happens generation is tight. So Octopus buy your electricty at 15p and sell it for more.

But as I said won't happen often. Also is your calculations don't forget losses involved in charging your battery. 5Kwh in does not give you 5Kwh out.

Edited by irc on Monday 31st October 11:23

Edited by irc on Monday 31st October 11:24

Thanks - so fixed outgoing Octopus at 15p/kWh and Agile Outgoing Octopus at - presumably - bugger all when the sun is shining and quite a bit when it isn't.

[DonkeyApple]

dmsims said:

DonkeyApple said:

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

No you can't

I know It serves to highlight which entity in the relationship has the means to capture any arbitrage potential. It's not us, the punter.

[Condi]

DonkeyApple said:

I know It serves to highlight which entity in the relationship has the means to capture any arbitrage potential. It's not us, the punter.

Equally Octopus are paying you 15p/kwh when wholesale prices might be 10p/kwh. Its not about arbitrage opportunity, but risk management, go on Export Agile if you want a price which reflects the market. Octopus have a tariff for most risk appetites.

[dmsims]

Our bill for September would have been 58.74p a unit (had we been on Agile)

irc said:

dmsims said:

DonkeyApple said:

Octopus have raised their purchase price to 15p in the last month.

So now you can buy at night from Octopus at 7.5 safe in the knowledge you can sell it back to them at 15p. It's free money.

No you can't

Possibly you can. Rarely.

[Derek Chevalier]

DonkeyApple said:

Tobermory said:

I'm not so sure that local solar is so much worse than commercial as the equipment is pretty similar (the efficiency of the panels is similar) and commercial solar has to be manufactured and shipped etc.

For sure local solar is much worse than commercial wind or nuclear, no question.

Yes, I do see your point. If we get to a stage where the grid is as renewable as it can be then yes there would be no benefit in local solar and it could be potentially harmful. I'm just not sure we are anywhere close to that yet (the current UK grid mix produces around 200g CO2 per kWh of electricity) and so there is a window to make it work, and for sure there is a geeky fun element in it too.

For the record if there was a scheme whereby you could invest in additional commercial wind power or nuclear and get a 'dividend' similar to these savings then that would be a much better arrangement, but I'm not sure this exists.

Edited by Tobermory on Sunday 30th October 22:48

Yup. Solar, whether retail or commercial has the issue in the temperate U.K. that it's generation is not well aligned to usage but wind has a similar issue. But, centralised production will be much smarter than millions of small, private set ups as you can imagine.

I agree 100% with you that it would make much more sense to invest in commercial renewable generation than to become our own inefficient producer.

Rather than sticking a whole load of landfill stuff on our roofs and then having to pay for our own control system and have the whole fiasco of it producing the most when we typically need it the least, not being able to efficiently store it, having days when we basically need to bin the excess and other days when it's not enough, investing in the same capacity a bit like a big solar farm allotment where solar generation is optimised, set up as efficient as possible, like maintenance and where every electron generated has a known value would be much better.

However, setting up a scheme such as that would reveal the financial reality and that's arguably why it's not been done.

But this is why investing in the blue chip, dividend businesses that not only pay good dividends but have no choice but to work towards being as close to 100% renewable as possible is probably a better option until PV becomes more efficient and cheaper as well as energy storage becoming more efficient and cheaper.

For me, as I just can't work out where the yield is on becoming my own power generator or energy trader and can't get the justification for the enormous capex requirement to stack up, I'd prefer to invest the funds into the efficient producers.

For example, if I have £10k that I want to allocate to helping offset by utility costs and also want it to be carbon efficient then I'd look at this sort of investment:

£10k worth of SSE.L. It would cost me no more than £10 in broker fees to invest and because it's not a capex based investment, at any time I can take my money back. The value of that £10k may fluctuate but unlike capex it's not on a fixed, guaranteed trend to negative where it becomes worth zero but has a cost of disposal. In reality, over time the value of that £10k instead of trending to zero and below will increase. There's next to no carbon footprint to the investment either. In this case the stock yields 5% so from the outset you're earning a utility bill offset of £500/annum while retaining your original £10k.

Unless someone has the perfect roof angle and pitch, the perfect personal energy usage that maps solar generation well then in very many cases, investing in the U.K. blue chip utilities is typically going to deliver better as well as safer returns while being carbon neutral.

Its hugely tempting to be one's own power station. For me, the enormous temptation is to become an energy trader. Arbitrage trading and risk management has been my livelihood and it's tremendously appealing to sit there accumulating cheap, unwanted electricity into storage and then selling it to desperate peak buyers but that doesn't work either because the massive arbitrage only exists precisely because we can't actually store electricity efficiently. It's the entire nub of the issue we face.

The closest that I've got to is utilising the battery of an EV to compensate for the huge inefficiency of using an EV with a massive battery for those anomalous journeys when day to day you only actually need a tiny battery.

I find the whole area fascinating but do feel that there is an enormous obscurity on the numbers both fiscally and environmentally. I just don't see how it can be more environmental and I'm adamant the financials don't add up.

Projects such as yours are genuinely interesting and I hope you find the time to publish the data as the more of that there is from individuals heading down this path the greater the clarity will be.

Does the same apply to a non-PV home energy storage solution (from both cost and environmental POV)?

Assuming I have a house using (a lumpy) 10000KW/h per year, 75% during the day and 25% overnight. That's 7500KW/h of dirty(?)/expensive power. If I could use a battery array (I've given up on using the milk float for car-to-home charging) to charge overnight at 12p, rather than 40p during the day

https://octopus.energy/go/

that's going to give me a >£2k saving per annum. A 20Kw/H battery is around £15k installed, so ignoring battery degradation, efficiency losses and future electricity costs, I'd probably get payback in under 10 years.

[irc]

Derek Chevalier said:

that's going to give me a >£2k saving per annum. A 20Kw/H battery is around £15k installed, so ignoring battery degradation, efficiency losses and future electricity costs, I'd probably get payback in under 10 years.

Have you included the finance costs. Say 5%. - £750. So your savings are down to £1250 a year. Counting what you are losing by not saving/investing that £15k.

Tesla claim 92% round trip efficiency. Be a bit cycnical and say 90%. So another £200 a year savings gone.


£1050 a year.

So roughly break even at 20 years assuming it lasts that long.

Other assumptions include the current large day/night difference existing long term as more EVs are charging overnight and some big generators like old nuclear close without replacement.

It may be the case that future price variation is windy v non windy days and for all of our sakes I hope the number of low wind high price days are few.

[DonkeyApple]

Derek Chevalier said:

Does the same apply to a non-PV home energy storage solution (from both cost and environmental POV)?

Assuming I have a house using (a lumpy) 10000KW/h per year, 75% during the day and 25% overnight. That's 7500KW/h of dirty(?)/expensive power. If I could use a battery array (I've given up on using the milk float for car-to-home charging) to charge overnight at 12p, rather than 40p during the day

https://octopus.energy/go/

that's going to give me a >£2k saving per annum. A 20Kw/H battery is around £15k installed, so ignoring battery degradation, efficiency losses and future electricity costs, I'd probably get payback in under 10 years.

I've not been able to get the sums to add up.

I don't see any point in trying to be a French utility company but the idea of using storage to arb the market all day, every day is of appeal.

The windows for buying cheap night rate power are quite short and I also suspect that firms like Octopus wouldn't be a huge fan of you hoovering up lots of 7.5p power at night when they need you to be buying at 45p during the day to balance their book making projections out.

But it's the cost of the batteries and their short life expectancy and subsequent disposal cost that is the killer that prevents the arb.

You need a lot of KW storage to make it worth while and then you need to be able to fill them very aggressively within the limited window and then discharge to near empty. The cost of set up is huge and the activity shortens the lifespan. You're laying out thousands, tens of thousands to make pounds in reality.

It's like charting, everytime you meet someone who says it makes money they eventually reveal they're leaving out a crucial detail that reveals the loss making activity.

[MaxFromage]

Derek Chevalier said:

that's going to give me a >£2k saving per annum. A 20Kw/H battery is around £15k installed, so ignoring battery degradation, efficiency losses and future electricity costs, I'd probably get payback in under 10 years.

You have to consider degradation. It'd be the same as running a car for 10 years without factoring in depreciation. I understand LifePo4 are designed between 2,500 and 7,000 cycles, so depending on the spec of the batteries, they could be dead after 10 years.

[irc]

If battery storage and realease made sense it swould already be done on a scale. The big batteries that do exist make there money by grid balancing where power is needed quickly and for short periods of time.

https://www.vice.com/en/article/epneq4/a-tesla-big...

[Dave Hedgehog]

irc said:

If battery storage and realease made sense it swould already be done on a scale. The big batteries that do exist make there money by grid balancing where power is needed quickly and for short periods of time.

https://www.vice.com/en/article/epneq4/a-tesla-big...

the problem is they found they could make a fortune by filling on green elec and overnight on cheap rate and then sell it all during peak times at high rate so its often close to empty at peak time

[Derek Chevalier]

DA, MaxFromage, irc, thank you. I'd love for it to be viable, but as you say, looking at the numbers it just doesn't work