How Green is EV ownership

[Dborn]

The problem arises if you physically cannot put sufficient panels on your roof. I have 6kwh, and would prefer 15. I have 1 Powerwall and 3 would see me through. I can’t put more up there, and even swapping to the high yield panels would only increase my system by 2kw.
To get the return on investment, eco cloud, you are correct, but you need to be able to ensure you are not pushing up daisies for at least 10 years after install.
Ideally, new homes are DESIGNED for solar.
In Israel where solar hot water has been a feature for 70odd years, the tanks/panels have been an eyesore. Not the close coupled systems we see here. New construction includes a niche on the roof to accommodate the units which “disappear “. The same principle needs to apply here.

 

[nwdiver]

@ShockOnT - Elon already said what he thinks re China on solar and why it can still work:

That fact you can easily generate enough energy from the sun to power the world surprises anyone in 2018 is an indictment of our science standards....

 

[EcoCloudIT]

@nwdiver agreed....

Even those with no roof space (not big enough, living in apartments etc.) have other solutions as they can push their state/federal governments for exactly what Elon was talking about in the video I shared...maybe even subsidised local batteries at homes/balconies with renewables coming in from solar/wind etc. farms....countries where solar is not as effective again have other means for renewable generation.

I find it interesting that Sweden was used as an example that solar would be difficult when in 2014 50% of their grade was produced by renewables....their nuclear reactors have gone from 12 in 2005 down to only 3 as of today....renewables is on a high uptake including solar:

Solar power (Sweden)
While installations have historically been minimal, solar power has recently been growing quickly in Sweden with the country's cumulative PV capacity nearly doubling in 2014 to 79 MW. Capacity rose further to 205 MW at the end of 2016.

In solar we are in Australia, and should be, way ahead of Sweden, however in total renewable uptake and government incentives/push we are way behind, for gods sake our government is still talking up "clean coal".....when in fact we have f%$king dirty coal or bloody dirty coal (AKA clean coal)....there is no such thing and never will be "clean coal"

If we in Australia would only be half as good as Sweden! We have no excuses.....

 

[Blue heaven]

Yes but id be curious as to his solution for densely populated countries that don’t happen to have a desert within power line range, such as South Korea, Japan, England, Singapore, Italy, Greece, Switzerland, or any country with a long dark winter like Estonia, Latvia, Finland, Canada, etc.

But the real showstopper is storage. Even a country as perfectly suited for solar as Australia cannot store the energy.

Back of the envelope, if Australia uses 10kWh per household between 4pm and 8am, and there are about 5 million households that’s 50 gWh of storage needed. That’s around 5 million powerwalls.

Installed that would cost $50 billion, with replacements needed every 10-15 years.

About 3 coal plants could service that same overnight burden. 2GW each is 6GW, which in 16 hours overnight is 96gWh.

Even the big Tesla battery in SA has enough storage for 10 minutes or so. You’d need 100 of them just to overnight that low population state.

The amount of battery storage needed in Australia is often over estimated, the first aspect is to make full use of the Eastern states grid that is spread over a wide expanse North to South, East to West, secondly install a suitable mix of solar, wind and hydro spread across that vast area, price the electricity to take pressure off peak demands and continue to educate building owners on energy efficiency, plus remember Tesla's may not be vehicle to grid but most other electric vehicles will have that option.

 

[paulp]

The problem arises if you physically cannot put sufficient panels on your roof. I have 6kwh, and would prefer 15. I have 1 Powerwall and 3 would see me through. I can’t put more up there, and even swapping to the high yield panels would only increase my system by 2kw.
To get the return on investment, eco cloud, you are correct, but you need to be able to ensure you are not pushing up daisies for at least 10 years after install.
Ideally, new homes are DESIGNED for solar.
In Israel where solar hot water has been a feature for 70odd years, the tanks/panels have been an eyesore. Not the close coupled systems we see here. New construction includes a niche on the roof to accommodate the units which “disappear “. The same principle needs to apply here.

Yes you are absolutely right, I designed our home to maximise solar that cannot be seen, which is why I’ve got 30 glorious kw, with space for another 5kw, albeit 5kw at 10% less effociency. The interesting thing is that if you install during the house build and use micro-invertors the price comes right down by avoiding the traditional solar companies. I’m tracking on sub 2 year pay back.
Looks like SA is aboit to get a 6k battery subsidy, so that will make at least 1 battery viable.

 

[Jays200]

Really green according to the AAA

Tesla Dominating AAA Ratings | CleanTechnica

 

[Vostok]

Solar looks cheap and feasible when it is shaving a few percent off a coal-fired powerstation, but to go 100% you need storage, which is horrendously expensive.

This is a long post, can be TL;DR for those not interested.

I’m getting solar and a battery next year, and built a fairly complicated model to do the financial modelling on it. The model uses an hour-by-hour solar generation profile, using one of the many excellent online solar tools which use your house location, orientation, roof pitch and local weather conditions to generate the profile. Obviously at any given hour it will be wrong but what’s important here is the statistical profile over the year will be very close to spot on.

Generating an hour-by hour consumption profile is harder when I don’t have a smart meter yet, but I used various methods to produce a profile that again hopefully has the right annual statistics and matched our quarterly consumption.

Then working out the hour by hour power flows between solar generation, household usage, battery charging/discharging and grid draw did my head in for a few days but I cracked it, and then could do all sorts of what-if analysis.

First result was that a 7kW system should generate over a year the amount of power we consume. Of course it won’t always generate it at the right time. Solar alone would reduce by grid draw by about 50% and had a payback time of about 6 years (I have to use expensive 360W panels to maximise power generation on my limited roof space).

Adding the battery was interesting. A Powerwall resulted in reducing grid consumption by 90% and only increased the payback time by 2 years.

Then being the nerd I am, I had a play with the variables. Turns out the optimum battery size (in terms of payback time) for my 7 kW system and usage profile would be around 8 kWh. The returns began to diminish fairly quickly after that.

To go off grid completely required both an increase in the solar system size (not possible with my roof) and battery size. To need grid power less than 0.01% p.a. (about 50 minutes per year) required a solar and battery system of about 50 kW and 50 kWh respectively. Clearly ridiculous, and resulted in export of huge amounts of power to the grid over the year, just to avoid drawing from the grid for the rare times when the sun isn’t shining much for a number of days in a row and the 50 kWh battery is run to empty.

What this told me is that individual households shouldn’t try to go off grid completely (unless there is a compelling reason to, or that household is happy to to run out of power occasionally or dynamically change consumption behaviour to avoid it happening).

So I don’t think we can get rid of the grid completely but mini-grids covering communities or cities could work. The killer for one household is the statistical “long tail” of trying to never run out of power at any time. Connecting together multiple generators and multiple consumers reduces the length of the “long tail” and improves the system statistics - it begins to look more Gaussian (law of large numbers) and then the problem is tractable.

 

[Shock-On-T]

This is a long post, can be TL;DR for those not interested.

I’m getting solar and a battery next year, and built a fairly complicated model to do the financial modelling on it. The model uses an hour-by-hour solar generation profile, using one of the many excellent online solar tools which use your house location, orientation, roof pitch and local weather conditions to generate the profile. Obviously at any given hour it will be wrong but what’s important here is the statistical profile over the year will be very close to spot on.

Generating an hour-by hour consumption profile is harder when I don’t have a smart meter yet, but I used various methods to produce a profile that again hopefully has the right annual statistics and matched our quarterly consumption.

Then working out the hour by hour power flows between solar generation, household usage, battery charging/discharging and grid draw did my head in for a few days but I cracked it, and then could do all sorts of what-if analysis.

First result was that a 7kW system should generate over a year the amount of power we consume. Of course it won’t always generate it at the right time. Solar alone would reduce by grid draw by about 50% and had a payback time of about 6 years (I have to use expensive 360W panels to maximise power generation on my limited roof space).

Adding the battery was interesting. A Powerwall resulted in reducing grid consumption by 90% and only increased the payback time by 2 years.

Then being the nerd I am, I had a play with the variables. Turns out the optimum battery size (in terms of payback time) for my 7 kW system and usage profile would be around 8 kWh. The returns began to diminish fairly quickly after that.

To go off grid completely required both an increase in the solar system size (not possible with my roof) and battery size. To need grid power less than 0.01% p.a. (about 50 minutes per year) required a solar and battery system of about 50 kW and 50 kWh respectively. Clearly ridiculous, and resulted in export of huge amounts of power to the grid over the year, just to avoid drawing from the grid for the rare times when the sun isn’t shining much for a number of days in a row and the 50 kWh battery is run to empty.

What this told me is that individual households shouldn’t try to go off grid completely (unless there is a compelling reason to, or that household is happy to to run out of power occasionally or dynamically change consumption behaviour to avoid it happening).

So I don’t think we can get rid of the grid completely but mini-grids covering communities or cities could work. The killer for one household is the statistical “long tail” of trying to never run out of power at any time. Connecting together multiple generators and multiple consumers reduces the length of the “long tail” and improves the system statistics - it begins to look more Gaussian (law of large numbers) and then the problem is tractable.

Thanks for your well written response. In a way I think we are on the same page.
There is a wonderful appeal to going off grid, but really we are all better off together. In fact, the only thing more efficient than the mini-grids you mentioned is “the grid”.
In fact, if only the grid was big enough to span the entire planet we wouldn’t even need storage. It would always be sunny somewhere, and always windy somewhere too.
To solve the emissions problem we need to take the easy wins first. Deploy solar until it exceeds power demand during the day. Replace slow coal with fast on/off gas. Subsidise wind and hydro. Enforce vehicle efficiency standards. Swap beef for pork, swap pork for chicken, swap chicken for veg. All easy, and reduces emissions quickly with little pain. Gives us time to work out the hard stuff like storage. Nanotube supercapacitor insulation bats anyone?

 

[Shock-On-T]

@ShockOnT

• Elon was referring to China, not the other countries you listed specifically, however many you did list are in a similar situation, secondly one doesn't always have to use solar, there is wave, hydro, wind to add to the mix etc.
• Storage is dropping dramatically in cost, we're only just started on this, 10 years from now maybe $50 a kw is achievable (with a break through or two)
• SA isn't meant to be a continuous supply system, it is meant to fix the peak price power gauging that occurs and it is performing spot on for this

We use 10kw's when the sun isn't shinning not including the 2x cars. Add the 2x cars to the mix and we're using 24kw when the sun isn't shining (assuming no day time sun charging on the cars).....therefore a 10kw solar array and 2x PW2 would effectively put us off-grid.....imagine in 10 years if battery storage for 20kw is only $2,000 (with profit and built in, inverter/thermal management etc.) and a solar 10kw system has dropped to $5k installed....would drop my average cost per month to $35 (assuming you replace the battery storage each 10 years and get 25 years out of the solar panels). Even in the dead of winter I'll be still effectively off-grid (and I'm Melbourne).....it's highly possible.....

Even 2x PW2 now is $23,000 installed, Tier 1 Solar 10KW panels is say $18,000....replace batteries each 10 years, assume no price drop on anything and over 25 years (under full warranty on the lot) the average cost is $250 per month.....this will give one an average of 29kw of night supply and 25+ kw of day supply....if someone is using 50kw per day now that will cost on average around Oz drawing from the grid about $425 per month...I know these are big daily numbers on electricity use however as we all move to EVs the norm may be 2x EVs at home and using 50kw's per day will be closer to the norm.....it's what we use.

Thanks @EcoCloudIT for your calculations. I'm glad to part of this community which has a proper discussion of the numbers with a solution-based focus.
In that spirit I'd like to gently push back on some of your points. Remember, there's no pleasure without a little friction

Firstly, I know Elon was referring to Hong Kong, I remember that interview from years ago. That's why I mentioned those other countries. The ones without that ready solution of a nearby Gobi desert. For example, South Korea is relatively large (in population), and has no way to make enough domestic power other than coal/gas or nuclear. No friendly neighbours, not enough land for solar, wind or hydro. Any flat land is already growing delicious cabbages. No problem if they sell Galaxy S9s and buy fuel, but a big problem if they want to stop emitting CO2. I can't see anything but nuclear for them.

Regarding the SA battery, my point is that it's humbling when you think that even such an expensive installation (if used as a storage solution) could only power SA for minutes. I brought this up to highlight the cost of storage, not the purpose of that installation.

And finally your estimates for solar/powerwall vs conventional seem a bit off. According to LG's system calculator (Solar System Output Calculator in Melbourne) you'd need a 33kW array to provide 50kWh/day during June at postcode 3000. Assuming your energy needs are still 50kWh/day in June, the system would need to be 33kW. Plus since you're only "effectively" off-grid you're still paying the daily supply charge to the dear old power company.

 

[lolachampcar]

In a previous life, Utilities were our primary customers (during the de-regulation days). Most of them lacked management and imagination so they either hired guns or brought on consulting companies to manage the transition. Once the transition was complete, they went back to their old brain dead ways. So, it really drives me nuts that there is a complete lack of imagination in most utilities and that they are so protected that thought is not required.

Specifically, I live in Florida. It would be a no-brainer for FPL to reach out to the more affluent service areas and offer to put solar on their customer's roof in exchange for locking in rates and even offering a rate reduction. I did my 10 KWdc for about $2.2/W owner builder using a PE for the wind load calcs, an electrician for the wiring and a roofer for the tie down points. I just assembled the racking and slung the panels. FPL has crews. FPL can design their own extrusions for racking. FPL can likely buy all of Canadian Solar's yearly production along with a good hunk of whatever inverter vendor they choose. FPL can do the engineering once then use their regulatory contacts to get a rubber stamp permit good state wide. In short, FPL can do what I did to my house at a fraction of the cost.

You start off in a neighborhood and, when you get to the point that you are a net exporter of power, you add a battery sub-station. Do this neighborhood by neighborhood. Re-invent yourself so you are relevant in forty years (ie. became a distributed producer). Reduce the demands on your grid so that one you have now, if well maintained, will work well into the future without needing to increase in capacity as the state grows.

The benefits go on and on but, like most things in the US, life has become too easy and there is no need to innovate or think to survive short term. We are more interested in rewarding stupidity. A shame really.

 

[EcoCloudIT]

Thanks @EcoCloudIT for your calculations. I'm glad to part of this community which has a proper discussion of the numbers with a solution-based focus.
In that spirit I'd like to gently push back on some of your points. Remember, there's no pleasure without a little friction

Firstly, I know Elon was referring to Hong Kong, I remember that interview from years ago. That's why I mentioned those other countries. The ones without that ready solution of a nearby Gobi desert. For example, South Korea is relatively large (in population), and has no way to make enough domestic power other than coal/gas or nuclear. No friendly neighbours, not enough land for solar, wind or hydro. Any flat land is already growing delicious cabbages. No problem if they sell Galaxy S9s and buy fuel, but a big problem if they want to stop emitting CO2. I can't see anything but nuclear for them.

Regarding the SA battery, my point is that it's humbling when you think that even such an expensive installation (if used as a storage solution) could only power SA for minutes. I brought this up to highlight the cost of storage, not the purpose of that installation.

And finally your estimates for solar/powerwall vs conventional seem a bit off. According to LG's system calculator (Solar System Output Calculator in Melbourne) you'd need a 33kW array to provide 50kWh/day during June at postcode 3000. Assuming your energy needs are still 50kWh/day in June, the system would need to be 33kW. Plus since you're only "effectively" off-grid you're still paying the daily supply charge to the dear old power company.

Thanks @ShockOnT, however:

Home Solar
Postcode 3000 isn't as good as 3145 Secondly, those Solar System Outputs are averages based on good/bad panels, good/not ideal direction, good/bad pitch etc....point is they are averages....I am lucky that I have a massive north facing roof, 30% pitched roof with zero shadowing and will use the highest efficient LG panels...in winter I will achieve around the 50kw's and in summer over 80kw's.

When I said effectively off-grid I understand sometimes I will not produce enough energy and will draw from the grid however at other times of the year (around 3-5 months) I will pump more than 30kw's per day back in to the grid. Do the figures and you'll see my reason for using the wording effectively off-grid....

China
My wife is Chinese, I've spent a lot of time (I mean a lot) all over China and just outside of Shanghai (China's largest city) there is vast land mass for wind/solar installations (I mean massive potential)...as a matter of fact you don't have to drive far to Ningbo (only a 2-3 hour drive from Shanghai) and you see the hundreds of wind turbines majestically turning.

SA
I only like to point out the strengths/weaknesses of a system based on it design....not what it wasn't designed for....on track to be cost neutral in 3-4 years...that's one hell of a quick payback....

 

[Vostok]

Thanks for your well written response. In a way I think we are on the same page.

Cool, thanks.

There is a wonderful appeal to going off grid, but really we are all better off together. In fact, the only thing more efficient than the mini-grids you mentioned is “the grid”. In fact, if only the grid was big enough to span the entire planet we wouldn’t even need storage. It would always be sunny somewhere, and always windy somewhere too.

This would be true if we could transmit power with zero loss. But we can’t, not yet at least (research on high voltage superconductors has been going on for more than a decade, I’m not confident we’ll see it at a feasible cost). The optimum grid “size” depends on lots of moving parts, what we have today is built on having very few and very large generation sources. Solar changes that completely and also virtually eliminates the need for exotic solutions like high voltage superconductors.

Deploy solar until it exceeds power demand during the day. Replace slow coal with fast on/off gas. Subsidise wind and hydro. Enforce vehicle efficiency standards.

The first is pretty easy to do, now that commercial solar is over 20% efficiency, and will only get easier. Subsidies are almost not needed any more. Vehicle emissions standards are something we urgently need, and squeezed every year until ICE can no longer survive.

Swap beef for pork, swap pork for chicken, swap chicken for veg.

Meat eaters should eat more ‘roo. Very lean meat, high in iron, very low carbon footprint (roos can’t be farmed), and helps manage the ‘roo population.

 

[Shock-On-T]

Thanks @ShockOnT, however:

Home Solar
Postcode 3000 isn't as good as 3145 Secondly, those Solar System Outputs are averages based on good/bad panels, good/not ideal direction, good/bad pitch etc....point is they are averages....I am lucky that I have a massive north facing roof, 30% pitched roof with zero shadowing and will use the highest efficient LG panels...in winter I will achieve around the 50kw's and in summer over 80kw's.

When I said effectively off-grid I understand sometimes I will not produce enough energy and will draw from the grid however at other times of the year (around 3-5 months) I will pump more than 30kw's per day back in to the grid. Do the figures and you'll see my reason for using the wording effectively off-grid....

China
My wife is Chinese, I've spent a lot of time (I mean a lot) all over China and just outside of Shanghai (China's largest city) there is vast land mass for wind/solar installations (I mean massive potential)...as a matter of fact you don't have to drive far to Ningbo (only a 2-3 hour drive from Shanghai) and you see the hundreds of wind turbines majestically turning.

SA
I only like to point out the strengths/weaknesses of a system based on it design....not what it wasn't designed for....on track to be cost neutral in 3-4 years...that's one hell of a quick payback....

You are right, 3145 is at least 50 metres further north than 3000!
Your case for lots of solar on the roof is totally correct, at this stage we really can't have too much solar. We could probably go to 30 or 40% before we hit the wall. The wall is the high cost of storage for whole cities/states. During the day solar is easily competitive with coalt, but it will still be orders of magnitude cheaper to just burn coal overnight than to use stored solar (unfortunately).
As for China, aren't we saying the same thing? That China would be fine? My point is that other countries don't have those advantages.

 

[nwdiver]

During the day solar is easily competitive with coalt, but it will still be orders of magnitude cheaper to just burn coal overnight than to use stored solar (unfortunately).

Coal is ~$0.03/kWh. Stored energy is ~$0.10/kWh... not quite 1 order of magnitude...

We should have batteries for $100/kWh capable of ~5000 cycles before we hit the wall for solar expansion... that's ~$0.02/kWh.

 

[Blue heaven]

Even if Coal powered electricity was free the consequences of burning it will never be cheap.

Coal is ~$0.03/kWh. Stored energy is ~$0.10/kWh... not quite 1 order of magnitude...

We should have batteries for $100/kWh capable of ~5000 cycles before we hit the wall for solar expansion... that's ~$0.02/kWh.

 

[EcoCloudIT]

@ShockOnT didn't realise you are staying the same as I re China....however other countries can still use renewables, will just be a different mix.

In terms of 3145....try 14km's - 20km's depending on ones location in Malvern East....however 3000 being the middle of the city it is all tall buildings that even if you had a house would be over shadowed.

 

[Shock-On-T]

Coal is ~$0.03/kWh. Stored energy is ~$0.10/kWh... not quite 1 order of magnitude...

We should have batteries for $100/kWh capable of ~5000 cycles before we hit the wall for solar expansion... that's ~$0.02/kWh.

That’s heartening news.
$0.10/kWh storage checks out for powerwalls (in 10s, 10,000 cycles, $10,000, 10kWh storage = $0.10/kWh).
So if storage price can drop three-fold it will be competitive will coal. That seems likely within 10 years or less, and it will take about that time to saturate solar.
Of course if all the negative externalities of coal were factored in it would be more that $0.03/kWh so would make these numbers even better.

 

[Dborn]

That’s heartening news.
$0.10/kWh storage checks out for powerwalls (in 10s, 10,000 cycles, $10,000, 10kWh storage = $0.10/kWh).
So if storage price can drop three-fold it will be competitive will coal. That seems likely within 10 years or less, and it will take about that time to saturate solar.
Of course if all the negative externalities of coal were factored in it would be more that $0.03/kWh so would make these numbers even better.

Those figures were USA ones..... ours may be different.

 

[Shock-On-T]

@ShockOnT didn't realise you are staying the same as I re China....however other countries can still use renewables, will just be a different mix.

In terms of 3145....try 14km's - 20km's depending on ones location in Malvern East....however 3000 being the middle of the city it is all tall buildings that even if you had a house would be over shadowed.

No, some countries cannot go 100% renewable, and don’t have access to a neighbour that can. That’s why South Korea has 23 nuclear reactors, producing zero CO2

Those figures were USA ones..... ours may be different.

Those are just my very rough numbers based a cost of $AUD10,000 for a powerwall, a capacity of 10kWh, and 10,000 cycles.
All very rough, just to the nearest order of magnitude.

 

[nwdiver]

No, some countries cannot go 100% renewable, and don’t have access to a neighbour that can. That’s why South Korea has 23 nuclear reactors, producing zero CO2

100% nuclear is far more difficult than 100% renewable...