Podcast: Play in new window | Download
Subscribe: RSS
This is where solar power shines: providing power needed by the site, on the site, without the grid.
I remember clearly the horror I felt when the truth about the new-generation solar panels from the well known company of Solar One Illinois was revealed to me which was quite surprising to hear as it was so good. It was a field day of sorts, at a farm, during which we were learning about a massive solar installation, sufficient to power not only the house and barns but an array of commercial freezers and refrigerators. Older solar panels required thick cables to route their 12-volt output to an inverter that changed the voltage to 110. But these new panels, we were told, each contained its own inverter and so yielded 110 volts without the need for thick cables or an external device.
It was only later, and tangentially, that the downside of this new development was revealed. Someone said something about how nice it must be to live without fear of the grid going down. The response was that well, actually, if the grid went down this enormous solar array would stop producing electricity because the solar panel’s inverters required an external power source to function.
This makes perfect sense, apparently, to most of the people who have installed or considered installing solar panels over the last several decades. The essential question they asked was how much money can I save, typically “How long will it take me to get my investment back?” No one ever asks this about a car, or a washing machine, but for some reason it became imperative for solar power installations, no doubt because salespeople found that it was far easier to motivate their customers to save money than to save themselves (from the fragility and pollution of the grid).
(I fully understand why people offered a substantial reduction in their cost of living would find the prospect attractive. But I believe they fundamentally misunderstand the true value of solar power.)
The approach has been industrialized in the US by national go-go companies such as Vivint Solar, Sunnova and the faded former juggernaut, Solar City. It spread to other industrialized countries as well, notably the United Kingdom, where by the summer of 2017 Britons were congratulating themselves on producing fully one-quarter of the electricity they consumed via solar panels.
The bloom is well off that rose. The BBC is reporting this week that “thousands” of solar-panel customers are complaining to financial-services regulators that they have not realized the savings they were promised when they bought to panels. Most took out loans to do so, but were assured that the reduced cost of their electricity would not only pay off the loan but pay them substantial cash dividends as well.
Two of the top-selling purveyors of the well-financed solar panel arrays, PV Solar UK and MyPlanet, were out of business by 2017.
With all due respect to the people who were fast-talked — both in the UK and here in the US where the chickens have not yet come home to roost — any scam requires people willing to be scammed, and to be blunt, you asked for it. You told them what you cared about most was money, so they told you what you wanted to hear and you bought it. Now you haven’t had your investment returned, but you do have a reliable source of free electricity on your roof, which is going to be incredibly valuable when the grid goes down next. Unless of course you have the new generation panels that don’t work if the grid is down,in which case you are just totally screwed.
I have always maintained that the real value of solar power is its insurance value, the ability it conveys to live without fear of a catastrophic loss of electricity. If your house does not burn down, do you complain bitterly about not recovering what you’ve spent on fire insurance?
Industrializing and commoditizing has done to solar power what it has done to everything else — just about destroyed it. The real value of solar panels is realized when they provide off-the-grid electricity to individual homes and businesses, either in the absence of grid power or as backup for the eventuality of grid failure.
Tom – we’ve had a solar hot water system for over 30 years and it has paid for itself multiple times. We also installed voltaic solar in 2003 with battery back-up and it did quite well thru the Sandy Storm while our neighbors were looking for gas to fill their generators. Over the years these systems have even turned a profit. We currently have free electricity for 8 – 9 months a year which is fairly good for an all-electic home. After Sandy we installed a generator to back-up the batteries in case the sun failed to shine or the panels were covered with snow. We have 44 years of data as evidence of the value of our solar systems. In my opinion the best bang for the buck is a hot water solar system – it is the most efficient. Best Regards, Russ
Interesting post Tom. We are completely off-grid, not so much by choice but by necessity. The cost of mains power is prohibitive – I would have to pay for 3 kms of poles and wires for one feed plus a mains transformer. So we have a hybrid system, solar panels, battery bank and a generator. Why do we have a generator – for peak load and the other thing the solar folk forget to conveiniently mention – available sunlight – yep the sun has to shine regularly and sufficiently. You also have to maintain battery systems etc etc. The solar panels were low cost, the batteries very high cost, the generator moderate. All up we are about equal on day to day running, that is what we pay for fuel etc works out to be about he same per kilowatt/hour as mains the difference – when we have full power we can use as much as we like without running up a bill.
As for a mains driven inverter panel – um what were these people thinking? Geez. As for cost savings forget it, energy is energy, law of thermodynamics, you have to play the game, you cant win and you cannot quit.
Heard a joke about this topic. A bank’s loan officer contacted Farmer Joe to ask for payment on his overdue loan taken out to install a solar system. The exasperated loan officer ask Joe why, for the duration of the five-year loan, he hadn’t made any payments, to which Farmer Joe replied, “I was told when I bought the system that, after five years, it would pay for itself!”
Conventional grid-tied arrays shut down during an outage not because the inverters need external (i.e., grid) power to function, but because there are safety concerns if an array (especially a big one) continues to energize a feeder all the way to its substation if the larger grid is down. But arrays can be “islanded” – i.e., instantaneously disconnected from the grid – and continue to operate a micro-grid that includes batteries. There are lots of examples of this now, on many different scales. The key is batteries, a major area of growth.
Also, I don’t know anything about whether solar policy worked in the UK, but it’s all in the policy design, and there are now many states in the US (e.g., Massachusetts, Vermont) where net-metered solar is paying for itself, delivering on its promises, and driving steady, reliable solar distributed generation on scales ranging from single homes to large, multi-MW arrays.
(Yes, I work in the industry, but I honestly don’t directly encounter the problems Tom highlights. At the same time, all other things being equal, in NO WAY does solar offer us a panacea so we can continue with our current level of energy intensity and material consumption into the post-fossil era…)
Ralph – your last observation is also the major over-rider – BAU. My view is that lots of folk go solar, some because they are doing the right thing others well they think they will save a buck, but I never here anybody ever say well there will be a compromise – you cannot continue to just use energy like it is therefore unlimited (the Free tag gets them all the time). So they do not change their energy consumption habits and never save a dollar as a result.
We were forced to change and down grade our energy demands to what we can produce, and that means using it when we have peak and load shedding when we cannot, that is not using stuff so our wiring and energy use pattern has changed significantly. We look at any electrical item not for what can it do but how much energy will it require (And there is a lot of bullshit on those labels – like the 600W toaster that blew the fuses with an overload demand that required 6 kilowatts to trigger, or the 800w thingy that triggers the upload demand on the generator telling me that it is drawing probably 3 KW. And so it goes. We are so used to a profligate energy consumption pattern we cannot think of minimal use or no use at all.
solar PV is neither “green” nor “renewable” since it is only a downstream extension of the hydrocarbon powered industrial infrastructure.
because of this, we work very hard to minimize our electrical consumption. we use less than 14 kWh/day so our 31 year old, 4.5 kW system easily has us at zero energy… includes our space heating and cooling needs.
but sadly, no one talks about reducing consumption or doing energy audits anymore, so now solar pv is mostly about powering waste and justifying non-negotiable lifestyles.
so while not “green” or any kind of “magic solution”, our solar electric system does add to our personal resilience as a buffer against grid outages. pumping water from our well for irrigation or firefighting is important to have backed up which is why i spend so much time and money keeping the system operating.
Out of curiosity, what powers the central inverter in a conventional system? The battery bank?
Yes
I love the ads for these panels, usually showing one on a patio, plugged into a utility outlet. It makes it appear that the panel is feeding electricity into the house.
“They” don’t want us to be self-sufficient. That’s why commercial systems shut down in an outage. The safety thing is just an excuse. Rather than sensibly disconnecting the house from the grid, they disconnect the panels from the house!
Don’t tell me they can’t tell if a line has power. If they were really worried, they could simply avoid restoring power until sundown and avoid all possible risk.
I’m a little disappointed in your assessment here. Sure, outages (and apocalypse) may be of concern. But the real advantage of solar PV right now is that it can reduce reliance on a fossil-fuel-powered grid. In my opinion, grid-connected solar PV should be expanded as much as possible for the sake of the PLANET. As for power outages…the devil is in the batteries. Power storage is still a huge limitation.
My gripe is not with connecting the solar array to the grid, but with doing it in such a way that the array does not work in the absence of the grid. Like the nuclear power plants that will melt down and blow up in the absence of the grid, this strikes me as a) misguided and b) a relatively simple engineering problem.
“But the real advantage of solar PV right now is that it can reduce reliance on a fossil-fuel-powered grid.”
um, how did you miss the reality that magic solar pv is 100% dependent on the underlying, unsustainable, hydrocarbon powered industrial mining and manufacturing foundation?
please stop worshiping technology. it is no savior.
Tom: Yes, the solution is simple and cheap, a transfer switch that shuts off the connection to the grid during outage. Most systems have this now.
Todd: True that technology is no savior. Do we need transitional technologies? Maybe. Damning solar (and wind, as in Tom’s next article) because of the resources they expend to be built might be more meaningful if you compare it to the resources spent in building conventional power plants/grids.
Hi Tom,
Thank you for writing this. The house that I live in has not been connected to the mains electricity grid for over a decade. For the vast majority of the year I rely upon solar photo-voltaic panels to produce enough electricity in order to charge the batteries that provide stable electricity to the inverter that supplies electricity to the house. It works, but even at a latitude of 37.5’S and with slightly over 6kW of panels, I enjoy only a fraction of the sort of average daily electricity consumption that most people treat as the norm. And during the depths of winter when the sun is low in the sky, it can be a bit touch and go depending on how cloudy the winter weather is (and it varies from year to year). And maybe once or twice per year I may have to run a fossil fuel generator due to thick cloud cover (some years I don’t have to).
For those who are curious, 37’N is the northern border of Arizona or New Mexico. Hmm.
And I would love for one person to say to me that they’d like to install solar PV panels for the sake of the environment, and then just go and do it (and stop talking about it).
But mostly the solar grid connected folks are kidding themselves. They’ll always say: “I produce about as much energy as I use”, and I ask them, so where do you get the electricity at night to run your air conditioning (I don’t use such a device despite the heat)? On batteries, I have to be careful what electrical devices I use at night because the more you use batteries, the shorter will be their lifespan.
And batteries are a really old technology and so there probably isn’t any easy gains or advances to be made, and they certainly don’t work like a fuel tank (which is how most people think of them). I prefer to imagine that batteries work like a deflating balloon where the air pressure becomes lower (voltage) as the balloon deflates.
Cheers
Chris
At very nearly 49N, I don’t plan to attempt solar power. But there are houses around with with their roofs covered in solar panels. A house we had came with a complicated solar water heating system that used 2 tanks & at least one pump to mix the the water to the set temperature. Lovely, but once it failed, the replacement cost was much higher than putting in an electric water heater.
Quick note that home solar is a better option for electric generation than burning coal in a central plant. For the planet and for the grid. Decentralized production allows for much less transmission line loss. In the past 10 years, we’ve lessened our CO2 emissions by almost 1 million pounds. Solar is part of the answer — not all the answer. It’s us to each of us to do our part.
Total carbon dioxide emissions in the US increased by 3.4% in 2018 (according to the Washington Post) and energy-related emissions went up by 2.8% (according to the EIA). So the planet is not a whole lot better off. Nevertheless, I agree that solar is the right choice, I’m simply arguing that we will make better choices if we are focused on saving ourselves rather than saving money, or the planet.