Earlier quoted context omitted.
Just pass those negative prices to customers and they will solve the problem.
That requires "smart" meters everywhere.
In the Netherlands smart meters are the default now.
Rooftop solar power may be flooding the grid
81–90 of 99 posts
Re: Rooftop solar power may be flooding the grid
#82This is a tough and awkward problem, because accounting for the externalities of a "good thing" would curtail progress towards a good thing. Meanwhile, the externalities of bad things get a free pass. Ouch. The solutions are either very expensive, very counterproductive, or very unfair. The expensive solution is grid energy storage, where the utility installs a bunch of storage to time-shift some of the generation to…
A better solution is to find a way to use the excess energy. If it gets cheap enough (zero or negative spot prices) you can just run any inefficient process once you have built the facilities to run that process.
A common example is hydrogen production. It's far less efficient as a form of storage than batteries or pumped hydro. But it has other uses beyond storage. Desalination, electric heating for heavy industry as alternative to heating with fuels, etc. are other ways.
Basically, we need consumer-side technology that can take advantage of fluctuating availability, not just producer-side adjustments.
Re: Rooftop solar power may be flooding the grid
#83Interesting. In Australia do people regularly install rooftop solar installations without also installing battery units? What's the logic there? Just selling it to the grid?
Well, grid feed-in can lead to faster repayment and smaller bills, but it's only 20-25% of the electricity price, so generating enough to be in credit relies on paying off the usage you have when the solar isn't generating enough for storage, or to offset your grid usage.
i.e. If you use 10kwh from the grid, and export 40kwh, you should get credit on your energy bill, but it's never that ideal, and some of the providers cap the export to 5kw/h for residential solar.
Most Australian energy providers have flat rate, some are on smart metering with peak/Time of Use rates;
The benefit of a battery isn't as immediate if you're not on peak rates. For those states which do have Peak/ToU rates, there are calculators that can show the amounts saved over 10-20 years, but it's still around 12 years to pay off a battery and solar install with the current pricing, not enough to cover the warranty or the useful lifespan of a battery in the same period. i.e. In 6 years, we'll have a next generation Powerwall or a competing technology, or something even cheaper, etc to store energy.
The solar rebates mean that even a smaller solar system is cost-effective in a smaller payback period.
The amount of the rebate has started to reduce, but a 4kw solar install will have a rebate around $2400 AUD ($1800 USD) off the price of the install, which usually comes to around 25-30% off the total cost of $5000 AUD, around USD $4200.
Prior to the half-price chinese panels coming into the market, the break-even was around 8-10 years, even with rebates. Cheaper panels have reduced the payback window to 4 years in some cases, even if the actual performance is not even close to the system's size,
ie. their real-world performance might only be 3.4kwh on a 4kw system, and the real-world payback might be closer to 5 years, due to changes in energy pricing affecting the returns, but also handling the problems like difficult installations, replacing/handling faulty hardware, or having to service the system if it fails in Australian weather conditions.
You can also find aggregates for these prices on sites like https://www.solarchoice.net.au/blog/residential-solar-pv-pri... which contrasts costs and pricing across states, and also accounting for variables like labour and electricity pricing, etc. Most solar systems with the rebate can be USD $3k to $5k for a smaller home install, and the system can be paid off within 4 years, 5 years if you want reliable parts.
Energy Pricing in Australia depends on state and providers, but is around USD 20c per kWh depending on state and supplier, with some areas having flat rate, others requiring net metering and peak/offpeak times
There's also a grid connection cost of USD ~70c/day, while Feed-in of solar PV generation is around USD 6c to 10c per kWh, which will probably drop to 5c/kWh in July. An earlier solar generation scheme had dual/gross metering and USD 45c/KWh feed-in rates, but this was discontinued in 2016.
Add to this, residential systems often have to get special approval from their energy company for things like 3-phase solar installs, require limiting exports to 5kwh, restricting to 90% output for Grid stability, sic. etc.
There are no rebate programs for the batteries, and there's a cost hike for importing the Tesla Powerwall 2, for no particular reason.
Compared to the AUD $9,000 to $11,000 AUD cost for the PW2 install, and despite it being better value, there are smaller, but similar LG Chem RESU batteries, which are more affordable and easier to obtain.
Re: Rooftop solar power may be flooding the grid
#84Renewable energy is quite predictable: there is sun during the day, and no sun during the night. Wind is a bit less but could be too. Why not organise accordingly? First, there are batteries: solar roofs should come with batteries, than will power the house during the night. Authorities could enforce that, and could also build larger energy storages with batteries at a region level (see recent examples from Tesla). T…
This is the part where someone points out why I'm completely wrong: > solar roofs should come with batteries The way I understand it, batteries tend to be bad for the environment if/when they need to be replaced, because often they are improperly recycled and/or there are no adequate facilities for that. If this is correct, do we really want to have more of them around? Wouldn't an environmentally-friendly(ish) centr…
Well, it really depends on the kind of battery.
I don't understand why these utilities are not creating a centralized battery in the form of, for example, pumped water. Use excess energy in the day to pump the water up, and let it down when the current energy demand exceeds standard production rates.
Pumped water is not the only possibility either, there are plenty of alternatives which are not terrible for the environment. See: https://en.wikipedia.org/wiki/Energy_storage
Re: Rooftop solar power may be flooding the grid
#85Earlier quoted context omitted.
This is the part where someone points out why I'm completely wrong: > solar roofs should come with batteries The way I understand it, batteries tend to be bad for the environment if/when they need to be replaced, because often they are improperly recycled and/or there are no adequate facilities for that. If this is correct, do we really want to have more of them around? Wouldn't an environmentally-friendly(ish) centr…
Well, it really depends on the kind of battery. I don't understand why these utilities are not creating a centralized battery in the form of, for example, pumped water. Use excess energy in the day to pump the water up, and let it down when the current energy demand exceeds standard production rates. Pumped water is not the only possibility either, there are plenty of alternatives which are not terrible for the envir…
Pumped storage relies on having a suitable natural basin, building one is far too expensive.
Quick googling suggests that Australia is already looking at this: http://www.abc.net.au/news/2018-06-06/tasmanian-pump-hydro-s...
Re: Rooftop solar power may be flooding the grid
#86Earlier quoted context omitted.
Decentralized is not really the problem here: it's more about the links between each installation and the surplus. It's harder to see it with electricity, but think as if it was water for example: if people were pumping water at home and pushing it into pipes to others, and not that many water was actually needed, where would it go?
By decentralization I mean something different, decentralization of energy production. The fact that, say, a village can decide to install a solar panel array to satisfy some of their energy demands, and they don't have to rely on powerful (and often global) energy companies who mine coal or process oil, is an important game changer in terms of power relations between people.
You just have to buy the solar panels from a global megacorp instead.
Don't get me wrong, this kind of decentralisation can be very effective in small isolated communities such as the Scottish islands, but for most places doing it locally is both more difficult and more expensive.
Re: Rooftop solar power may be flooding the grid
#87Please note that there are powerful lobby groups in Australia that have interests in fossil fuel businesses and promote journalism that exaggerates problems with renewable energy. Eg see this: http://artsonline.monash.edu.au/climate-change-communication...
Just as there are powerful interest in solar and wind. Edit: To the downvoters. What are you disagreeing with? Are you claiming that the wind and solar industry doesn't have special interest and that they aren't powerful especially when you look at the support it has politically?
People are generally familiar with the self-interest of the fossil industry, but you seem to be saying that everyone who supports renewables is also in it for the money? Without evidence?
Re: Rooftop solar power may be flooding the grid
#88I am in my 5th year of a 9.8MW system. I have generated about 45MW of power and approximately 1/3 stays in my home and the rest is sold to local power company.
A couple of years after installation I started to see negative press for solar and eventually some action by my local power company. "Solar is no use to me", to quote the manager. Their actions finally killed new solar in our town. They used arguments like this, but we all suspected they were worried about revenue protection. There are 7 solar customers, a gnat's cock, so-to-speak, but they are/were scared. Local newspapers echo sentiments that solar customers have their hands in the pockets of non-solar and provide no balance.
My goal is to get a 10-15kWh storage (Tesla Powerwall probably) and then keep most or all of my power and pay the grid like a very low usage customer. I believed we could do better, but I don't see it happening.
Re: Rooftop solar power may be flooding the grid
#89Earlier quoted context omitted.
Just as there are powerful interest in solar and wind. Edit: To the downvoters. What are you disagreeing with? Are you claiming that the wind and solar industry doesn't have special interest and that they aren't powerful especially when you look at the support it has politically?
People are generally familiar with the self-interest of the fossil industry, but you seem to be saying that everyone who supports renewables is also in it for the money? Without evidence?
What do you want evidence for? Are you saying that those who invest in solar or wind do not have a self-interest in what they invested in. That seems to be a much bigger claim that the very obvious that any investment you make you have a self interest in.
Climate gate should have made it quite obvious that no one is excempt from bias. Thomas Kuhn wrote a whole book about it.
Re: Rooftop solar power may be flooding the grid
#90Earlier quoted context omitted.
>liquified air energy storage. I wonder if this may be helpful. Let me answer this: No, it would not be helpful, because on pretty much all metrics (capital and operating costs, efficiency, flexibility, size etc) this technology is way worse than battery storage. Unfortunately - today - a lot of money which could be sensibly used deploying cost effective technology such as solar and wind power (and to a lesser extent…
What do you make of the claim that this technology is better for long term storage than battery storage?
I see what they are getting at. My initial thoughts are:
1. There will be considerable losses in storage. Evaporation in LNG tankers is around 0.05-0.1% of their cargo capacity per day. This is around the same as the self discharge rate for Li ion batteries, which have higher cycle efficiencies.
2. The claim could be that the overall cost of complex liquefaction equipment to use up a little bit of energy per day over say summer months combined with large relatively simple storage tanks to hold the liquified air until say winter could be cheaper than having very large batteries. This is possible... but:
3. This would have to compete with for example production of hydrogen by hydrolysis, which would be cheaper, easier to store, and have similar cycle efficiencies.
Finally: Consider that none of the current LNG import terminals attempt to extract energy from the re-gasification of liquified gas. This seems to be the low hanging fruit of liquified air technology, but it is not economically attractive. So I sincerely doubt that the described scheme would make economic sense.