And that just encourages development of an automatic switching system such that power generated on site is always used on site. It never goes out to the grid until after 100% of local demand is met, and all local storage devices are topped up.

And that, in turn, would encourage those customers to just go completely independent from the grid and either find some other flexible use for excess power or shut down excess production.

Pretending that local power is using grid infrastructure does not make it so. People can and will disconnect from the grid to disprove that lie.

I'm surprised this area of smart switches aren't more available or popular.

I've done a small amount of research because I could not find a smart charge controller with AC inputs and I was considering making one with a Raspberry pi.

I did however find a smart air conditioning split system that uses solar panels directly and gets any extra power from 120v ac plug: https://www.practicalpreppers.com/air-conditioning/ac-dc-air...

It's quite effective because when the sun is shining, that's when indoor cooling is needed the most.

> People can and will disconnect from the grid to disprove that lie.

More and more municipalities are making this illegal. To protect their utilities, they require that you tie to the grid and sell all electricity you generate to the grid and then buy it back for more.

Can confirm...when I was living in AZ the main argument against net metering is that the Utility company would suffer...nevermind the fact that solar users would benefit, the state legislators and ACC (Arizona Corporation Commission) always sides with the utility company.

Well.... they've made grid-tie solar untenable, but off-grid solar is becoming more viable with products like the Tesla Powerwall. Costs aren't low enough to make it financially viable for most people, but for new construction that faces high costs to run utility power, it can already be cheaper.

By discouraging grid-tie solar, utilities may be shooting themselves in the foot as off-grid becomes more affordable.

Assuming a normal electric consumption, an off grid solar system costs $30-40k more than grid tied. Furthermore, the batteries won't last forever. (That's assuming electric cars, heat pump, basically an all electric household.)

You gotta be far in the woods to save money!

Yes, if you're selling product to a wholesaler, you should expect to be paid wholesale prices. The alternative is just a subsidy.

To be clear, the law is such that you can't use any of the electricity you generate while it's still "yours." You have to first sell it to TVA (and get paid X) and then buy it back from TVA (and pay X+Y.) In other words, you have to pay $Y to use your own electricity.

That's not what the linked article says. The linked articles says that if you want to feed the grid, you're only going to get wholesale prices, while having to pay retail for the energy you consume from the grid. It's a rule of accounting.

If you don't want to eat the premium, don't feed the grid. That is, consume your electricity before it ever hits the meter(s). Presumably the real issue is that typical consumer systems aren't designed to function the way you'd want to avoid the TVA accounting rules.

As Tesla Powerwalls and similar home battery systems become widespread, it will be easier than ever to self-consume the majority of your energy needs.

how can they possibly prevent you from using the current from a solar panel?! are you legally obligated to tie a meter to it that you can't control?

Those regulations (99% sure they're regulations, not laws) apply if you want a grid-tied system. If you are off-grid, you can do whatever you want.

On the other hand, wheat you grow for use on your own farm should offset the cost you pay at retail to buy supplemental wheat.

If you are generating 5kw and using 4kw only 1kw gets sent to the grid. So you are not selling those 4kw at wholesale prices and buying it back at retail. Only the power that is time shifted gets this treatment.

You are free to buy batteries to do your own shifting. Also remember that wholesale costs typically just account for power generation, while retail costs also account for grid maintenance. An owner with solar is benefiting from grid maintenance, so it makes sense that they contribute.

Now from a societal perspective you may want to subsidize solar. But it certainly isn't "unfair" to buy power at wholesale and sell it at retail.

Unfortunately this is not the case! TVA has a "sell all buy all" rule, that if you are connected to the grid and generate 5kw, you are required to sell all of those 5kw to the grid (at wholesale price). Then you buy back the 4kw you use (at retail price). It doesn't matter if you were only using your own generated power, you still pay. Crazy! I didn't believe it the first time I read it either, but that is really the law they adopted.

All the rule does is prohibit net metering. If you never sell your power on the grid it's irrelevant. So you're free to use your 4kw directly.

Presumably this is a hassle because most equipment is designed for net metering where the system is setup to feed all generated capacity to the grid and consume all energy directly from the grid. So without net-metered billing, to avoid paying the retail premium you'd probably need a very expensive system that eliminates the cost effectiveness.

In fairness, AFAIU most utilities despise net metering. From their perspective they're the ones getting screwed, and the TVA billing system more fairly compensates them for infrastructure costs.

Even crazier. In France, the setup is similar: you sell all your energy to EDF, and they sell it back to you. I don't know if that's still the case, but a few years ago, the KWh you pay to them was cheaper than the KWh you sell.

If the selling and the buying happens at different times, then that doesn't seem so crazy. The real cost of electricity is dependent on supply and demand - which varies with time.

In certain parts of USA demand is especially high when the sun is at it's peak and most places on earth see low demand in the middle of the night.

According to the link sent by eppp TVA doesn’t allow net metering.

Edit: I got the terminology wrong. I agree that expecting net metering (“free” time-shifting) is not reasonable. And it seems that in addition to the “sell all, buy all” solution it is also possible to sell (or buy) only what remains after (or is required for) local consumption. https://www.tva.gov/Energy/Valley-Renewable-Energy/Dispersed...

Net metering is not the same thing as only paying for what you use. Net metering means you could push 4 kWh during the day and draw 4 kWh overnight and get metered as zero consumption from the grid. This pushes a storage and distribution cost onto the utility and its other customers. Paying you at wholesale for the daytime push and charing you at retail for the nighttime draw moves those costs back to you.

What others are saying above is that you could generate 4 kWh during the day and consume it on premises, i.e. with air-conditioning or other day time appliance use, and still have zero consumption from the grid. This is also the point of the powerwall and any other on-premises energy storage.

That's true when you're using the power as you generate it, but when you sell it back to use later, you're essentially buying power storage. Efficient power storage is harder than efficient wheat storage, so they're not very comparable.

This seems the most fair way to handle power that is not generated by the utility. If the consumer wants to cut themselves off the grid and have enough extra solar panels and batteries to be self sufficient, that should also be allowed.

Years ago somebody explained to me the same here in Germany and I was shocked that they allow crooked laws like this.

You mean they don't allow rich solar panel owners to get their grid battery subsidized by poor folks who lack the capital for their own solar?

This is a good thing. No power company should be forced to pay retail for power. It is a regressive tax on those that can least afford it. I don't think it was inappropriate to offer to get the industry off the ground, but it's quickly approaching the time to do away those subsidies - especially those that come directly from other rate-payers.

Nor should the power company force customers to buy the power that they generated themselves at the utility's price.

They already paid the capital costs for generating their own power. You want them to pay again? For the transmission lines and peaking plant that they aren't using?

Certainly, when the net usage is negative, the utility should pay only the wholesale cost of that portion of production in excess of local usage. When the net usage is positive, the customer should pay the retail price of that portion of usage in excess of local production. But it is nonsensical for the customer to sell the power they generate at wholesale, and immediately buy it back at retail. Immediate use should not be metered in either direction, and time-shifted use should account for peak vs. off-peak.

Otherwise, all you are doing is forcing the customer to use bigger batteries to route around your obnoxious local generation policy.

That "grid battery" is actually the natural gas fuel supply at the peaking plant that does not need to be used to supplement the baseline plant. Fuel that stays in the tank instead of being burned is the best "battery" we have right now. If you encourage people to use their own redox reaction batteries, you're lowering the efficiency of the entire system, and everyone loses.

The article is an advocacy piece andit turns out isn't telling the entire story. The rules are described here: https://www.tva.gov/Energy/Valley-Renewable-Energy/Dispersed...

There are 3 options:

>Self-Generation The electricity produced serves the facility’s needs first. Any excess electricity is delivered to the power grid without payment. If the facility needs additional electricity, it must be bought from the local power company.

>Self-Generation and Dispersed Power Contract The electricity produced serves the facility’s needs first. TVA purchases any excess electricity that is delivered to the grid. If the facility needs additional electricity, it must be bought from the local power company.

>Dispersed Power Sell-All Contract All of the electricity produced and delivered to the power grid is sold to TVA. The facility buys all of its electricity from the local power company. (Two meters—one for electricity purchased by the customer from the local power company, and one for electricity generated by the customer and sold to TVA—are required.)

So no one would ever choose option 3, and no one would choose option 1, unless the installation was so small that the capital cost of the dual-channel meter would never be recovered. If it were truly the customer's choice, this would not be an issue, because the customer should always prefer #2 to #3.

So what does TVA do (if anything) to get customers to pick #3, or force them into it?

Also note that net metering is not an option. #2 uses a dual-channel meter to track outgoing power separately from incoming power. Net metering is not necessarily the optimal metering solution, either, but TVA doesn't even offer it.

Hmm, I think you may be confused/arguing against a strawman here, but I'll bite.

> Nor should the power company force customers to buy the power that they generated themselves at the utility's price.

No one is forcing customers to do this. I'm not sure where you get that from? If you are using more power than consuming, it does not leave your local premises. Only the excess power you are not using at that point in time is being sent. That's kind of the point of net metering.

> Certainly, when the net usage is negative, the utility should pay only the wholesale cost of that portion of production in excess of local usage.

Which is precisely what they do. Some are forced to pay retail - which was a temporary subsidy both to spur solar development and honestly was adopted largely due to billing convenience if nothing else 20 years ago. Easy to just let a meter spin backwards and bill/pay based on those numbers vs. developing entirely new billing software but everyone knew at the time it was temporary and financially nonsensical.

> When the net usage is positive, the customer should pay the retail price of that portion of usage in excess of local production.

Currently the case.

> But it is nonsensical for the customer to sell the power they generate at wholesale, and immediately buy it back at retail.

This isn't the case anywhere I've heard of, and definitely not the TVA. Even the linked article very clearly describes the situation as net metering as defined everywhere else. Customers are not sending all their generated power out their meter, then putting load on the "grid" on another meter back in. That would indeed be absurd.

> Immediate use should not be metered in either direction, and time-shifted use should account for peak vs. off-peak.

Completely agreed.

> That "grid battery" is actually the natural gas fuel supply at the peaking plant that does not need to be used to supplement the baseline plant. Fuel that stays in the tank instead of being burned is the best "battery" we have right now.

Yes and no. You might be surprised solar load does not match up nearly as well with peak power demand as is reported. This of course is a fine point to debate, and generally is in your favor.

My main point is that power companies being forced to operate a free battery for rich solar customers is immoral when think of who is subsidizing that free battery. Rooftop solar may be about the least valuable form of power to a power company as they can do nothing to schedule production, and the rest of the rate-payers shouldn't be forced to pay retail rates to the rich few who prefer to save $15k on a local battery pack so they don't need the grid battery at night.

I don't think we should force folks to require battery packs, but I also know that the financial incentives are currently lined up to have us end up with a bunch of rich folks paying nothing for power with solar systems, and a bunch of poor renters paying for 100% of the capex on things like the nuclear baseload plants so the solar folks get power at night.

I feel like you didnt read it.

"Thus, any grid-tied solar system within the TVA region must have dual metering, one to measure power coming off the grid, another to measure power going to the grid. The arrangement with TVA is likewise “buy all, sell all” in that you have no choice but to sell all the power you generate to TVA, then you buy back whatever you actually consume."

That is exactly what TVA does.

That is what "buy all, sell all" means.

http://midwestenergynews.com/2017/01/24/indiana-energy-bill-...

Yep, I was mistaken. I didn't reach the end of the article apparently the first read.

I do agree that is problematic and silly.

> Customers are not sending all their generated power out their meter, then putting load on the "grid" on another meter back in. That would indeed be absurd.

That is exactly what the linked article claims is happening to TVA customers: "Thus, any grid-tied solar system within the TVA region must have dual metering, one to measure power coming off the grid, another to measure power going to the grid. The arrangement with TVA is likewise “buy all, sell all” in that you have no choice but to sell all the power you generate to TVA, then you buy back whatever you actually consume."

How is it crooked? The utility company pays to builds and maintains the grid infrastructure with the expectation they can use the infrastructure to sell power to consumers.

One person selling back some unspecified amount of solar with questionable reliability, without the utility company having any say when the power is provided, isn't exactly a very useful thing for a utility company, so it's surprising they even pay the same wholesale rate.

Why not get a basic battery system and use that to power some loads in your house, instead of buying power from the utility company for those loads?

You're not allowed to use the electricity you generate. _All_ power you produce is sold to the utility at wholesale. _All_ power you consume is purchased from the utility at retail. Two separate meters.

Wait what? How? Is this a Tennessee specific thing? This seems absurd and impossible to enforce.

If I hypothetically spend a couple hundred bucks on a solar panel, 12v lead acid battery, and basic 12VDC -> 120VAC inverter, put those items on a wagon, and drag it across my yard to use power tools where an extension cord won't reach is the power company going to arrest/fine me? Is it only illegal once I use the batteries/inverter under my own roof?

If i understand the article correctly, it's illegal when you wire it to the grid. So, powertools and a battery will be fine. i suppose you could have a big switch outside your house that lets you pick local generation or grid generation, ala a datacenter failover switch.

But nobody wants that. Really, i don't think many people care about selling the power back either. But they've made it already, why waste it? What people want is i'll make the first 5 kwh, and i want to buy any extra from the grid. And i don't want a big switch system for each light in my house. Which seems very normal and sane.

>But nobody wants that.

Oh, that's exactly what I want, and have been researching for myself. I'm taking it even further and planning on being able to switch individual circuits between battery and grid.

If that idea is dumb somehow I'd love to know more resources about why. From my perspective it's a better solution than grid tie, but I value resiliency and reliability as well as pure cost alone. If I still lived in a city where the power literally never went out for years at a time, then having a local backup would not be really attractive.

And considering the regulations, it seems like the system I'm considering would also be able to basically satisfy the desire for "i'll make the first 5khw". Select a circuit that draws at least 5 kwh/day, run it off batteries until the battery bank voltage drops below a threshold, and then switch over to the grid.

> Oh, that's exactly what I want

Hah. Existential quantifiers are hard.

I’m not an electrician, and that’s who you should talk with.

However, it’s way easier to just trip a breaker when the power goes out. The whole neighborhood is drawing from your battery, breaker flips and you are done.

A single meter tie is simple. You use what you generate. Any extra makes the meter run backwards. You draw more, you pay for it. The infrastructure probably can’t handle whole neighborhoods doing this.

IMHO, they should charge a flat monthly fee for the option to connect.

If there's an electrical link between your system and the public grid, you're playing by the grid's rules. If you don't want to play by the grid's rules, you can't connect to the grid in any way.

p.s. Even if buy-all-sell-all doesn't make sense, requiring your electrical setup to meet grid standards does make sense. It's be surprisingly easy to cause a blackout, or to kill yourself, by messing it up.

It’s up to the states to decide I guess. In my state, the local power company lets you use what you need and then sell what you don’t use at whole sale rates.

They will send you a check if you produce more than you consume. I’m not sure if you had to pay for the meter but they would install one.

PG&E here in Northern California does offer net metering -- sell to them when the sun is up and buy back at night, guaranteed a wash in $$. Good deal for us.

This could be because of the Commerce Clause in the Constitution. It basically regulates all commerce at scale in the US of A. I bet TVA took its position because of Roscoe Filbrun, a wheat farmer with a similar argument in 1942. This is a really great piece on it if you're interested.

http://www.radiolab.org/story/radiolab-presents-more-perfect...