Excellent example of why solar panels (in the right locations) and LEDs are a better investment than the S&P500 right now. You spend dollars now to eliminate the need for future dollars.

While that is true, keep in mind that future dollars are less expensive than present dollars.

But it stands to reason that the prices of energy will rise faster than the rates of inflation, so it would still be a good investment.

If everybody buys solar, electricity prices will only rise faster than inflation in periods without much sun.

It might even be profitable to play a 'buy when it is free or cheaper, use when it costs money' strategy. You can get there by buying large batteries, charging them from your neighbor's solar panels when there is lots and lots of sun (they may even sell at prices below zero), and discharging them, selling to you neighbors, when there is little sun and wind.

I'm already investigating buying 50+ MW at a time of Tesla Powerpacks in certain markets exactly for this purpose, as an independent generator. Buy power when people are paying you to take it, releasing it back to the grid at the most expensive times.

Unlikely. Solar Panels don't replace all of your electricity costs. Naturally, you'll still run your refrigerator at night, right?

And during the day, when you have peak-solar energy, you'll be at work and won't be taking advantage of it. You'll recoup some of the costs through net-metering, but you usually buy back at wholesale prices and not at retail prices.

Finally, I'd expect utility companies to change their pricing scheme in the near future to account for solar. They service your electrical wires for example, and you'll likely have to pay a certain amount of money for that. So while you're not buying "power" (or at least, as much power) as before, you'll still have the service cost of being hooked up to the grid.

Chuck's sibling reply is spot on, but something else you must realize is that both renewables and energy storage are only going to get cheaper.

This means if utilities attempt to squeeze people with solar on their roof, they will simply move to batteries eventually. This already makes sense, today, in Hawaii (where the local utility was stalling on additional grid tie capacity, and with their per kwh rates so high, is was cheaper to go off grid). The more people who move off grid, the less people the utility can spread its costs across, increasing the rates for those remaining (which then rapidly incentives those people to move off grid).

This is called "the utility death spiral". Its a very real possible outcome, and utilities are aware of it. [+]

[+] http://www.greentechmedia.com/articles/read/this-is-what-the...

Indeed.

But what's to stop utilities from purchasing or creating cheaper large-scale projects?

I know you've seen my previous comments on Reddit with regards to Redox Flow batteries, CAES, and Pumped Hydro storage technologies. Utilities simply have access to battery-technology that the common people do NOT have access to. Some energy storage technologies only make sense in larger-scale 50MW applications or more.

If utilities serve a cooperative role in energy service, they will switch to the most cost-effective technology BEFORE the typical homeowner can switch.

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Basically, solar pricing is moving FASTER than rooftop solar. Rooftop solar will always require insurance and roof-workers, while solar utility companies can just buy out a field in the middle of no where and install solar on the ground.

Cheaper and safer for utilities to work with. And then everyone in the town benefits, instead of just a few rich people who can afford panels (and the insurance of the rooftop workers)

At some point the price for the panels will drop below the price (and losses) of the transmission lines to transmit the energy from the large-scale project to your house. This happened long ago if you live in certain parts of the Rocky Mountains, and it will happen in areas of progressively greater population density.

Rooftop solar only needs roof-workers and their insurance until you have a cherry-picker-style robot arm to stick the panels up there with.

Utilities have a lot of capital tied in their existing fossil fuel plants, and their economics are probably tied into running these at capacity for their remaining lives.

So from their perspective it makes sense to lobby politicians to stall residential solar as long as possible, the environment be damned.

Last time I checked, it was the motivation of utility companies to make money.

http://www.exeloncorp.com/companies/exelon-generation/solar/...

Look man, you may not notice it. But the big utility companies out there are investing heavily into solar.

You need to consider the economics of "grid tie" you generate excess power into the grid and "buy it back" when you aren't generating in excess. So if you generate as much power as your going to use for the entire day from your panels, you pay nothing for that day. Even though you are drawing power at night.

In the Bay Area, there are other things that screw up the numbers but the program "trues up" once a year (rather than monthly) so some months (usually late spring through early fall) I'm generating more power than I use for the month, and fall/winter I consume more power than I generate in a month. The target is to hit it at exactly 0 which was easier to do when PG&E would exchange kilowatts for kilowatts but it is harder now with their system of charging extra kilowatts over baseline. Its screwed up and not fair but I get that they are hurting, if I could get Elon to sell me the battery pack out of a Model S and the inverter infrastructure to go with it, I could leave the grid entirely and that would be easier.

That's the idea with the Power Wall, https://www.teslamotors.com/powerwall Unless that's what you're pointing out

> You need to consider the economics of "grid tie" you generate excess power into the grid and "buy it back" when you aren't generating in excess.

Depends on the state.

Sometimes, you buy at retail prices and sell at wholesale prices. Which honestly, is far more fair. You're basically using the utility's batteries / energy storage at no charge right now (if you're in a state with pure net metering laws)

And yes, purchasing a PowerWall is more "fair". Instead of relying on the service and tax-incentives to give you a free battery pack, its definitely more fair if you got your own.

"Fair" in the context of a heavily regulated utility should have some relation to social benefit.

It's not fair for utilities to force costs onto consumers just because of a differential of political influence. It's not fair that solar reduces grid load at their peaks and saves them money on building out grid capacity and expensive and inefficient CO2 producing gas peaker plants and that benefit is not returned to the provider of that service.

Overall the many benefits of rooftop solar can be calculated and a value assigned. Most seem to come out at net or above, so talk of average wholesale prices is misdirection.

Consumers should pay a fair price for the service.

If consumers are using the utility's batteries and the utility's network, then the consumer should pay for the use of those services.

Peaker-plants can have a very simple solution: carbon taxes. Simple enough, and I support this measure to handle the externality.

Rooftop solar currently is probably a net benefit as long as the storage issue isn't a problem. (IE: the rest of the neighborhood doesn't have solar). But once solar adoption is widespread, someone needs to solve the storage issue (or "energy waste", if there is no more storage)

I'm glad you support a carbon price, because that's another great example of where "fair" becomes a political discussion.

I could say that if a coal producer wants to dump sulphur, radiation, C02 etc. into the air then it's "fair" that they recompense the people who live in the countries they pollute and the people they help to kill. Why should those who don't do this (people who generate their own electricity or pay to have non-coal energy) have to shoulder these costs?

Simple argument right? But no, it's a decades long political fight with no end in sight, because some groups have dispersed interests, while other groups have very direct incentives.

The same is true here, lots more rooftop solar would be of small benefit to most people. But it directly threatens some concentrated interests. And they will happily tell you that solar will destroy the grid, or net-metering isn't fair etc. etc. Not because it's true, but because it's in their narrow and short term interests to lie.

The difference is that I also think that net-metering is an unfair deal to utility companies. Again, someone needs to build the energy storage mechanism. You can't legislate away reality.

Unless it's dorm-fridge-sized, you can definitely run your refrigerator only during the day, generating ice to cool it during the night. Building HVAC systems often work this way, running the chiller to generate ice during the night (when electricity prices are low or even negative) and running the resulting chilled water through heat-exchanger coils during the day. And superinsulated fridges like Sunfrost models can stay cool during the night even without such extra thermal reservoirs.

A thing I haven't seen, but which ought to be practical, is a solar thermal fridge — for example, using the ammonia-absorption cycle that propane-powered fridges use, but heated with sunlight instead of flames. PV panels are typically 16% efficient, but it's easy for solar thermal collectors to reach 50% efficient, and they're also about five times cheaper per unit area (still). So you'd think it would make sense to power the fridge directly from sunlight.

As an EMH guy, I'd like to think that if an Einstein–Szilard cooler was more economical than grid power for A/C and/or food refrigeration that there'd already be systems for sale.

There are absorption refrigerators for sale for food refrigeration — I had one in my Volkswagen — but I don't think they use the Einstein-Szilard design, but a simpler one. Here's one: http://www.amazon.com/Norcold-Inc-Refrigerators-N841-Refrige...

> And during the day, when you have peak-solar energy, you'll be at work and won't be taking advantage of it.

I'm in Central Texas and I have two dogs at home. Even if I'm not there, I still leave the air condition going so they are comfortable. The last time I checked, my A/C system was the biggest power hog and so my electricity consumption aligns very closely with when the sun is shining.

Biggest power hog? Yes.

But not the only thing. My point is that its way too idealistic to assume that 100% of the costs will be covered.

I mean, yes, the laws as written seem to encourage a 1-to-1 transmission of energy. "Net Metering" is a law that subsidizes decentralized solar energy.

But in the future, when the subsidies run out and the laws are written to be FAIR (instead of written to encourage solar, as they are right now), you will not be allowed to purchase electricity and sell electricity back at the same prices.

All markets have a bid-ask spread. Wholesale prices are always going to be cheaper than retail prices.

I'm not sure what you mean by 100% of the costs will be covered. All I know is that I can reduce the amount of electricity that I buy during the day when I consume the most. The savings are greater than the cost so it's pretty much a no-brainer for me at this point. If I finance, I can pretty pay for the system with the money that I'm no longer using to buy electricity.

> when the subsidies run out

Why stop subsidizing solar? Do you think all energy subsidies are going away, or just solar?

https://en.wikipedia.org/wiki/Energy_subsidies#Allocation_of...

I think that net-metering is going to go away once solar adoption reaches a certain critical mass. You can't keep giving away free batteries to consumers, someone eventually will need to pay for those batteries.

Other solar subsidies may remain a bit longer. But net-metering is probably the biggest once.

> I'm not sure what you mean by 100% of the costs will be covered. All I know is that I can reduce the amount of electricity that I buy during the day when I consume the most. The savings are greater than the cost so it's pretty much a no-brainer for me at this point. If I finance, I can pretty pay for the system with the money that I'm no longer using to buy electricity.

SunEdison's model has been proven to be incompetent. SolarCity's "MyPower" loans have been scuttled. That's WITH the current large number of pro-solar subsidies that the US Government is paying for.

I think that it's a "no brainer" to take advantage of SolarCity's deals as a consumer. But in the long-term, it looks like their finances are unsustainable.

Personally speaking, I'm more concerned about a long-term reliable model that manages to get the energy to the most number of people. Utility scale solar seems to be the best solution, although its a bit boring.

I'm not sure that the net metering argument applies to places like central Texas. People consume the most power when the sun is shining so solar, even without net metering, makes sense. Of course other regions are different.

> Utility scale solar seems to be the best solution

I don't think it makes sense to talk about a best solution. Large scale solar will contribute along with nuclear, coal, natural gas, wind, etc...

If you have space and money, you can create huge "gravity lamp" to store energy: lift up something massive using solar energy and electric motor, then it will slowly generate electricity at night using same motor as generator.

Or you can use "molecular spring", which is very compact, for same purpose.

How close are we to actually manufacturing molecular springs? My understanding is our materials science and engineering is not up for making macroscopic molecular springs yet, and what I can Google up seems to indicate we nowhere near macroscopic scale springs.

Make container of highly porous material then fill it with a fluid which will avoid that material surface at molecular level. AFAIK, it is invented years ago.

Can you post a link to that please? When I search around starting with the Wikipedia [1] entry, I don't find a description of what you are describing.

[1] https://en.wikipedia.org/wiki/Molecular_spring

http://www.google.com/patents/US7767301 http://dergipark.ulakbim.gov.tr/eoguijt/article/view/1034000...

> you'll be at work and won't be taking advantage of it.

Most people don't work in the dark

And presumably a lower bill implies lower energy usage, so he'd need fewer panels to cover it.