Solar ... In the news

Martyn1981

GreatApe wrote: »

What would save more fuel
£5k on a battery or £5k to expand a roof system by 4-5KWp ?

Hard to say. I'd expect the PV today, perhaps the battery tomorrow, depends on the amount of PV rolled out, the amount of storage, how the local grid (the DNO's (remember them)) is coping etc.

As with all in life, I assume the answer is an appropriate and timely mix of of resources.

BTW are you @cells posting under two names?

Martyn1981

Interesting piece on using PV to provide leccy services to the off-grid poor in rural Uganda.

SolarNow financing facility aiming to reach 70% of rural Uganda with off-grid systems

NigeWick

Martyn1981 wrote: »

Hard to say. I'd expect the PV today, perhaps the battery tomorrow,

Tony Seba reckons that the cost of on site solar + battery will work out lower than the cost of transmission in a few years.

As an aside, about a 6 month waiting list for a Tesla Powerwall 2 here. Get mine in March, if I'm lucky....

Martyn1981

NigeWick wrote: »

Tony Seba reckons that the cost of on site solar + battery will work out lower than the cost of transmission in a few years.

As an aside, about a 6 month waiting list for a Tesla Powerwall 2 here. Get mine in March, if I'm lucky....

Hiya, I was watching another Youtube interview involving Tony recently, it was at a solar show I think.

In Australia I think PV + batt has already breached the distribution cost 'God parity'* that Tony refers to.

In the UK I think no standing charge accounts are about 15p-18p/kWh, so knock off 4-5p for the wholesale price, and that leaves 10-14p/kWh.

For retro-fit I worked out that PV was heading for about 7p/kWh (25yr repayment mortgage base, at 2% (own money, but pricing in opportunity cost) and a replacement inverter etc). So storage costs need to get down to around 5p/kWh, which is certainly doable if costs keep falling.

* God parity is a pun on grid parity. It's based on the supply leccy becoming magically free, but PV and batts still cheaper. Interesting target, and looks doable depending on where you live and local leccy costs.

GreatApe

zeupater wrote: »

Hi

Odd really, someone I know has 5MWp of panels on one of his fields and I'm pretty sure that it's not 250 acres ... there's a 20MWp solar farm not too many miles away and that's on a couple of fields, not a 1000 acre country estate ...

A simple calculation would suggest that you've slipped a decimal point ... ie a 250W panel would be ~1.7mx1m so a power density of around 150Wp/sqm (250/1.7), so even allowing for 2/3 of a solar farm land area being taken up by access & margins, that's 50Wp/sqm of land area if the panels were flat-mounted, suggesting that you're assertion is seriously flawed ...

Maybe your starting point should be closer to 1/4 the size of London, but then again, the larger the solar installation, the better the overall panel:ground area ratio, so maybe closer to 1/8 the size of London .. throw in some ~300W higher efficiency panels & you're pretty close to 1/10th ... that suggests that your asserted land area could be in error by a factor of up to 40x and there's still be around 40% of the land area unused (simple Trigonometry) ...

HTH
Z

Why not just look at some solar farms that exist and the amount of energy they produce and the land area they take?

This is the biggest UK Solar Farm
http://britishrenewables.com/shotwick/
72.2 MWp
250 Acres

If you take 11% CF and do the math it works out to 7.9 watts per square meter of land

GreatApe

NigeWick wrote: »

Tony Seba reckons that the cost of on site solar + battery will work out lower than the cost of transmission in a few years.

Even if that were true (which is very hard to believe as the statement is saying that multiple 100kg+ battery packs lasting 15-30 is going to be cheaper than a few kg of copper lasting 300+ years) the reality is that there is not the capacity to offer the world that option.

For instance 2018-2030 might see close to 1 billion buildings built (mostly apartments) and all of them will have electricity. There is not the capacity to make 1 billion x 15KWh battery packs through the period 2018-2030 so even if batteries were cheaper than connecting to the grid there simply isn't the option for batteries as the capacity to make that many batteries does not exist and starting a new battery factory takes 5 years

Plus most the 1 billion buildings that will be built over 2018-2020 will be apartments with no roof to put solar on so they will need a grid connection.

The grid is not going away. Stationary storage for batteries is pointless outside of solar farms in hot nations. Stationary storage for places like the uk is a total waste just use your cash to install more solar where possible

GreatApe

Martyn1981 wrote: »

Hiya, I was watching another Youtube interview involving Tony recently, it was at a solar show I think.

In Australia I think PV + batt has already breached the distribution cost 'God parity'* that Tony refers to.

In the UK I think no standing charge accounts are about 15p-18p/kWh, so knock off 4-5p for the wholesale price, and that leaves 10-14p/kWh.

For retro-fit I worked out that PV was heading for about 7p/kWh (25yr repayment mortgage base, at 2% (own money, but pricing in opportunity cost) and a replacement inverter etc). So storage costs need to get down to around 5p/kWh, which is certainly doable if costs keep falling.

* God parity is a pun on grid parity. It's based on the supply leccy becoming magically free, but PV and batts still cheaper. Interesting target, and looks doable depending on where you live and local leccy costs.

why would the grid let you freeload?

I am sure you dont feel like you are freeloading but that is what you would be doing, if everyone did that then the grid would have to just charge higher and higher standing charges and you would have no choice but to pay it as your batteries dont get you actual security of supply.

People in the UK that install batteries are wasting actual resources (copper nickle lithium etc) and capital there is no need for it economically or ecologically it is bad. Just install more solar if you want to green the place

zeupater

GreatApe wrote: »

Why not just look at some solar farms that exist and the amount of energy they produce and the land area they take?

This is the biggest UK Solar Farm
http://britishrenewables.com/shotwick/
72.2 MWp
250 Acres

If you take 11% CF and do the math it works out to 7.9 watts per square meter of land

Hi

Actually I have looked at some solar farms, there's three 5MWp installations within a 20minute walk of where I'm sitting right now!

Your latest, modified postulation is that 72.2MWp = 250Acres. your last one was 5MWp=250Acres ... odd that there's around a 14:1 ratio differential .. !! .. also the 6W has moved to 7.9W, so 14:1 now becomes 18:1 ...

Anyway, what has capacity factor got to do with it? .. a panel generating under 1000W/m2 of irradiation generates it's rated power output, cf has nothing to do with the power .. if any form of generation is cost effective against other forms of generation then it's cost effective whatever the cf, so raising the issue is simple distraction or diversion.

What counts is not Power(W), it's Energy(Wh) !!

HTH
Z

GreatApe

zeupater wrote: »

Hi

Actually I have looked at some solar farms, there's three 5MWp installations within a 20minute walk of where I'm sitting right now!

Your latest, modified postulation is that 72.2MWp = 250Acres. your last one was 5MWp=250Acres ... odd that there's around a 14:1 ratio differential .. !! .. also the 6W has moved to 7.9W, so 14:1 now becomes 18:1 ...

Anyway, what has capacity factor got to do with it? .. a panel generating under 1000W/m2 of irradiation generates it's rated power output, cf has nothing to do with the power .. if any form of generation is cost effective against other forms of generation then it's cost effective whatever the cf, so raising the issue is simple distraction or diversion.

What counts is not Power(W), it's Energy(Wh) !!

HTH
Z

Are you for real?
Please go back spend a bit of time thinking and get back to me

I said 6 watts/sqm I did not say anything about acres
You suggested I was an order of magnitude out so I showed the largest uk PV farm is about 7.9 watts/sqm which is not that far out. If we use a CF of 10% as that plant is not in South England then its a figure of 7.1 watts/sqm

Anyway using the 7.9 watts/sqm figure you would need to cover an area of 4,770 KM^2 in non stop solar power to generate an annual 330TWh. By compassion London is 1,572 KM^2 and London has parks and reservoirs and rivers etc too so it isn't fully built up. You would need roughly >3 x the area of london in continuous non stop solar PV panels to generate the questioned 330TWh earlier on in the thread

zeupater

GreatApe wrote: »

Are you for real?
Please go back spend a bit of time thinking and get back to me

I said 6 watts/sqm I did not say anything about acres
You suggested I was an order of magnitude out so I showed the largest uk PV farm is about 7.9 watts/sqm which is not that far out. If we use a CF of 10% as that plant is not in South England then its a figure of 7.1 watts/sqm

Anyway using the 7.9 watts/sqm figure you would need to cover an area of 4,770 KM^2 in non stop solar power to generate an annual 330TWh. By compassion London is 1,572 KM^2 and London has parks and reservoirs and rivers etc too so it isn't fully built up. You would need roughly >3 x the area of london in continuous non stop solar PV panels to generate the questioned 330TWh earlier on in the thread

Hi

I suggest that you really do need to go away & research/understand the difference between power & energy, how they are measured and how information is communicated so that others have a clue what you're on about ...

Perhaps Cardew would be so kind as to instruct you where your error is ...

Good night !
Z