Solar is here to stay! It’s only going to grow and get much more common, and also less expensive as it grows and competition expands and costs come down for components as they become more common and widely available worldwide. Many solar companies will go from being a seller (middleman) of panels to becoming brokers of dozens of companies as they realize the more they can offer, the less people will shop around.
Power companies can get pissed off as much as they want, but the fact is companies like FPL, especially after this Hurrican Irma disaster that just went through Florida will be getting left behind by irate customers at their lackluster performance and taking weeks to get power back on for the citizens of Florida. Even after their billions in subsidies and so on, they still took too long. It’s yet another reason for people to Go Solar in Florida or elsewhere in the U.S.
Such a “rule” can be fought. It sounds like it’s using the individuals of the public to subsidize a corporation, which I am going to guess already gets huge subsidies through taxes. Taxes are legit, but each household being required to have a contract with a non-competitive company is far from it. Your own self-contained solar is literally a “utility service” anyway.
I will never have time to refute the vast amount of disinformation and misinformation in this thread.
So here are two key points.
unless you are Mr. Burns and can blot out the Sun, solar panels cannot be turned off. The power they make can be sent to batteries if you have a true off-grid system, backfed to the grid if you have no batteries, or sent to a diversion load. You cannot turn off solar panels. A household air conditioner is a perfectly fine diversion load, for one example, water heater elements are popular.
preventing home power systems from islanding is a solved problem. The system we installed at my kids school and the system we are currently installing in our church use normal, everyday anti-islanding inverters as required by code. They do not “turn off the solar” when the grid is out, because that would require turning off the sun.
Goodbye, I have systems down affecting multiple hospitals, can’t stick around.
I may have used the term “panels” rather than inverters a few times to try and make sure someone understood me.
That was a mistake. I also called it “solar”, when the term is “photovoltaic”. I apologize for the technical errors. I will make sure that I clarify these terms when I submit my comments to my IEEE working group.
Also, you don’t need “diversion loads” for PV. We frequently oversize PV panels to get longer maximum output from inverters. In other words, we might put 100kw(max) PV on a 50kva inverter. This insures that you can maintain 50kva for a longer period of time. You do not need to maximize output of the photovoltaic elements.
Yes. That is called IEEE 1547 compliance.
The photovoltaic panels are not "turned off’. The always exhibit potential. The inverter ceases to produce an output AC current.
Then again, this is a technology that confuses people so much that NEC cannot agree on the definition of a “panel”, so I don’t think you are going to see consistent terminology.
It absolutely can be fought. It probably will be fought.
However, only a fraction of solar installations are currently “off-grid”. Financially, the math is challenging and it isn’t exactly a reliable system. If you want it to be truly reliable, you need EVEN MORE panels and EVEN BIGGER batteries.
So, most people, even those who are totally “off-grid” still maintain a utility connection.
I seriously doubt FPL created this law strictly to screw with solar.
When I referenced a “hybrid” inverter, I was referencing the exact type of system you just linked.
I also have mentioned a specific product, the SMA Sunny Island, which can be used for essentially the same application.
The study was in reference to available geography. I am sorry I wasn’t clear. My point is that we have essentially “maxed out” the geography.
The 87% figure came from one old HECO(Hawaiian Electric Company) website.
The DoE labs put it at 80.4% in their white papers -https://www.nrel.gov/docs/fy14osti/60806.pdf
So, I would put it down lower at 80%. That isn’t great.
It is a little misleading to quote that lower number you saw for Li-ion batteries. That was from a paper on electric vehicle battery efficiency. The actual stated charge/discharge efficiency of a Li-ion battery is normally stated as >95%
Sorry, wikipedia has some very misleading information on this topic.
So, if you consider that someone fudged the number a bit high for your pumped hydro and fudged it a bit low for your lithium, then you see that it is actually a huge level of inefficiency. Then again, it probably doesn’t matter. But if comparing technologies to store energy: hydrogen<PHS<batteries
It’s very impressive for robust energy storage efficiency. 80% is awesome.
In the real world Li-ion is not optimally cycled, has a self-discharge rate that works out to around 10% loss a month even if it’s in a conditioned stable building envelope, needs a sophisticated battery management system that is not field maintainable, and requires periodic expensive replacement even in optimal conditions.
Hydrogen does not occur freely in nature; it has to be liberated from more complex materials, which requires energy input. It has pathetic energy density by unit volume, requiring more energy input to create safe storage, and over time it basically migrates through anything but metal (or even more costly materials) so all joints and seals have to be precision machined and matched to their vibration and temperature environments. Hydrogen total efficiency is abysmal in practice, even with modern fuel cells (that are generally extremely sensitive to membrane contamination and other costly failure modes); typically end-to-end efficiency of 20% in real world total analysis.
Meanwhile pumped storage has near-zero storage losses, low maintenance requirements for the impoundment, field-repairable pumps, turbines and generators, and if properly built can last hundreds of years. And it gets that awesome 80% efficiency you mentioned.
It’s misleading to compare laboratory efficiency numbers while eliding the differences in simplicity, maintainability and reliability. PHS, in the great many places where it’s possible, is better than batteries, and modern batteries are far better than hydrogen cycling. Hydrogen is a handout to petrochemical companies and other dirty energy producers masquerading as green tech.
Then you agree there is no good reason that solar installations without battery storage cannot power houses safely when the grid is down. It’s a completely solved problem.
I have no more time for this, sorry. Lots of high tech meatspace things to manage.
In case anyone else has the same confusion as @Medievalist
You absolutely can power a house or anything else without grid power. I said as much:
You can install them without a battery! But installing them without a battery is kind of a weird idea. You can power your entire house! for 5 hours a day?
The battery isn’t to store power from when the grid was operating, the battery is to store power from when the sun is shining.
There are a number of different ways to handle this entire hookup. At the end of the day, your entire system has to be certified by UL. That means that you can’t simply install a “switch”. The switching has to be internal to the system. This has to be a UL certified box.
Since this has caused A LOT of confusion, I invite anyone interested to watch a training video from Schneider Electric.
Hydrogen may or may not be those things.
At the end of the day, I can convert electricity potential energy for storage. My option are wide open, but the most common suggestions are as follows:
A battery is, theoretically, the most efficient. In the short-term and under ideal conditions, it has the highest theoretical charge/discharge efficiency. (You can bloviate about the need for a BMS and other stuff, but we should keep it simple. I am not an Alber salesperson.) It is also the most expensive to manufacture and high maintenance costs associated with many of the technologies. In no way am I saying it is the best technology. Portability sucks.
You really hate hydrogen! The good thing about hydrogen is hydrogen doesn’t “appear in nature” because it so readily oxidizes. It has to be liberated from “water”, but at a highly inefficient rate. Hydrogen is very inefficient. However, it combusts readily. Hydrogen is fantastic for certain applications, such as remote backup generators and other applications. However, the low efficiency makes it useless as grid backup. Portability and storage is good though.
It may have “pathetic energy density” by volume, but compared to what? Compared to a bucket of water it is fantastic. I would much rather power my remote gensets with hydrogen/batteries than PHS.
Installing batteryless grid-tied inverters with always on power isn’t abnormal; it’s routine. Being able to power HVAC, stoves, refrigerators and freezers only when the sun shines is extremely beneficial during grid failures and well worth the investment in many regions… such as hurricane prone Florida. When it’s dark, sleep, and don’t open the fridge. When it’s not, make ice.
Everything else you just posted is quite accurate, including the part about me hating the whole hydrogen scam the big oil companies like to push.
