Solar ... In the news

Martyn1981

silverwhistle wrote: »

If that can be achieved on an ex-council terraced house roof, think what could be achieved with more installations with the latest efficiency panels.

I've probably posted this before, but always worth a quick look. The site shows the amount of land area needed to provide all of the worlds energy (not just leccy) from PV in 2030.

It's based on 20% efficient PV. Mine varies from about 14-15%. Today's 'normal' PV (say 280Wp panels) are about 18%, and silicon perovskite should lift the figure to around 30%+.

Total Surface Area Required to Fuel the World With Solar


**Free Bonus** Scroll down the site and it also gives sea area for getting all energy from off-shore wind. This is based on 5MW turbines and approx capacity factor of 40%, but we are already heading for 10MW and 50%.

These illustrations are great for getting a mental image/idea of how little area needs to be 'lost' to these technologies.

NigeWick

GreatApe wrote: »

You will still need the grid for the winter months when your solar & batteries are not sufficent

But, not necessarily the National Grid. A local microgrid would allow me to export to neighbours who do not have solar or batteries. I am in the position where I can afford to add a lot more solar to my roof and store it in more than one Tesla Powerwall 2. At present, I use about half of the 4,500 kWh per year my system produces, by trebling PV capacity and adding battery storage I could actually manage through the winter too. And hopefully earn a little cash by selling summer's excess to neighbours.

I suspect that these things are not too far in the future as I believe there is already a company setting such a system up.

NigeWick

Martyn1981 wrote: »

The site shows the amount of land area needed to provide all of the worlds energy (not just leccy) from PV in 2030.

There's a Youtube video with Elon Musk showing the area it would take to provide solar electricity to the whole USA, without putting solar on rooftops. It's a pixel in Utah on a scale map of the US.

Martyn1981

NigeWick wrote: »

There's a Youtube video with Elon Musk showing the area it would take to provide solar electricity to the whole USA, without putting solar on rooftops. It's a pixel in Utah on a scale map of the US.

I watched his recent presentation at the battery park in Australia, he showed a map of Australia, big screen, with a very small box to represent the PV needed to power all of Aus. He said they couldn't show the battery farm needed as it would be less than a pixel. :cool:

Nicolai_Grenovski

Unfortunately, I have found that the sun doesn't shine on my solar panels after dark so I obviously believe that a battery system is a necessity. As I am connected to the grid and have Economy 7 I could also charge the battery on cheap electricity at night and discharge in daylight hours during winter when the panels are not producing anything like full capacity.

As it stands you can charge your battery without affecting your UK FIT so that's obviously better than using E7 for arbitrage (whilst you can) - although as solar+battery uptake continues I wouldn't be surprised to see that type of 'double dipping' be stopped
In fact, as more and more load is placed on the off-peak times (such as batteries in arbitrage mode as wel as EVs, it could well be that the utilities/government end the E7 tariff and self consumption of notionally exported electricity.

Nicolai_Grenovski

But, not necessarily the National Grid. A local microgrid would allow me to export to neighbours who do not have solar or batteries. I am in the position where I can afford to add a lot more solar to my roof and store it in more than one Tesla Powerwall 2. At present, I use about half of the 4,500 kWh per year my system produces, by trebling PV capacity and adding battery storage I could actually manage through the winter too. And hopefully earn a little cash by selling summer's excess to neighbours.

Wouldn't a better system be to have no 'home' storage and instead place all the batteries at the local substation so that power could be shared across all three phases?
Batteries charged from the low voltage (220v) domestic supply, inverted onto the 11/22kv supply and under the control of the grid operator.

In other words, a DSM enabling technology, charged by arbitrage and domestic microgeneration that can be used for 'peaking' (balancing) by the grid to the benefit of domestic and industrial users.

Nicolai_Grenovski

I watched his recent presentation at the battery park in Australia, he showed a map of Australia, big screen, with a very small box to represent the PV needed to power all of Aus. He said they couldn't show the battery farm needed as it would be less than a pixel.

Interesting yes, but it's more a visual demonstration of population density/solar insolation of how big and sunny the continent is.

Australia was never going to have a problem with space to put solar.

Nicolai_Grenovski

**Free Bonus** Scroll down the site and it also gives sea area for getting all energy from off-shore wind. This is based on 5MW turbines and approx capacity factor of 40%, but we are already heading for 10MW and 50%.

Larger wind turbines are not automatically higher cf than smaller ones.

The advantage is that an 8MW turbine is cheaper to build and install than four 2MW turbines and it is this that drives down the cost/MWh of wind - including the expected £57.50/MWh (*2012 pricing) bid for 2023.

i.e. -the world's largest wind turbine is/are Burbo in the United Kingdom with a cf of 31.9% which is actually slightly less than the main array average cf of 34%.
But they cost significantly less (even though they have to be spaced further apart) and require fewer support vessels for O&M over their lifetime.
http://www.4coffshore.com/windfarms/burbo-bank-extension-united-kingdom-uk59.html

Nicolai_Grenovski

zeupater wrote: »

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

Have you read Sustainability without hot air by David Mackay?

Very good, useful read.
Here's the section on solar
https://www.withouthotair.com/c6/page_38.shtml

Nicolai_Grenovski

zeupater wrote: »

Hi



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

cf (or load factor) is very important, which is why the power industry use it.
This is because CF is a measure of average system capability,it is not an instantaneous measure.

For example, if you split your pv to East/West inclined 35 degrees and has a cell total 5kwp then your actual simultaneous max cell power (p) is unattainable at any moment in time.
It is reduced to a system maximum.
That is the limitation of your situation and cf is the representation of that.
It is why (for example) a 5kwp system would not breach the domestic DNO 16amp limit.