Hurricane Sandy seems to have brought out the latent stupidity in just about everyone in their zeal to get in on the climate alarm resurgence. I laughed out loud when I read this op-ed in the NYT by DAVID CRANE and ROBERT F. KENNEDY Jr. published, December 12, 2012, because it becomes immediately obvious that these two “experts” don’t have a clue about how grid-tied solar actually works, and their ideas actually can cause deaths, injury, and additional property destruction if people try to follow their lead and then try to circumvent safety features when they find out their solar system won’t do what they claim. How embarrassing for them.
Excerpts:
[…]
Residents of New Jersey and New York have lived through three major storms in the past 16 months, suffering through sustained blackouts, closed roads and schools, long gas lines and disrupted lives, all caused by the destruction of our electric system. When our power industry is unable to perform its most basic mission of supplying safe, affordable and reliable power, we need to ask whether it is really sensible to run the 21st century by using an antiquated and vulnerable system of copper wires and wooden poles.
Some of our neighbors have taken matters into their own hands, purchasing portable gas-powered generators in order to give themselves varying degrees of “grid independence.” But these dirty, noisy and expensive devices have no value outside of a power failure. And they’re not much help during a failure if gasoline is impossible to procure.
Having spent our careers in and around the power industry, we believe there is a better way to secure grid independence for our homes and businesses. (Disclosure: Mr. Crane’s company, based in Princeton, N.J., generates power from coal, natural gas, and nuclear, wind and solar energy.) Solar photovoltaic technology can significantly reduce our reliance on fossil fuels and our dependence on the grid. Electricity-producing photovoltaic panels installed on houses, on the roofs of warehouses and big box stores and over parking lots can be wired so that they deliver power when the grid fails.
That last sentence in bold is my emphasis, because it shows just how clueless these people are when it comes to real world solutions. They want to give readers the impression that they can use their grid-tied solar power system after a storm to get electricity, I’m here to tell you that claim is absolute bunk.
Full disclosure. I have a grid tied solar power system on my home. I had one on my previous home, and I orchestrated the first ever solar power system for our local school district. I know a thing or two first hand from an engineering and use standpoint. Here’s my current home installation:
Top: the solar panels. Bottom: the DC to AC inverters and the grid tie and SmartMeter.
Note the red labels, particularly under the SmartMeter. They are required by law. The red one under the meter (along with the new yellow one added by the utility company after inspection for the grid tie certification) reads:
“Possible danger of electrical back feed” is the key phrase, one completely lost on the NYT, Kennedy, and Crane.
The issue is this, if you have grid tied power sources running in your neighborhood, and they are producing power, anyone who isn’t careful doing electrical work could get electrocuted thinking that after they pulled the main breaker, there is no power in the wires. Imagine if you have a bunch of these pumping power into power poles laying on the street after a storm; it becomes an instant fire starter.
But that’s been taken care of too, because the DC to AC inverters won’t function due to this (also required by law and code) safety feature built in. Here’s the relevant code from the inverter installation manual:
Electrical conformity according to U.S., Canadian and
international safety operating standards and code
requirements:
– UL 1741 – Standard for Inverters, Converters, and
Controllers for Use in Independent Power Systems
And this:
4.2 Protective concepts
The following monitoring and protective functions are
integrated in blue planet inverters:
– BiSI grid monitoring to protect against personal
injuries and avoid islanding effects according to UL 1741
What is “BiSI grid monitoring”? According to E DIN VDE 0126, which is a year 1999 standard developed in Europe specifically to address the problem:
The automatic disconnection device is used as a safety interface between the generator and the public low-voltage distribution net and serves as a substitute for a disconnecting switch accessible at all times by the distributing network operator. It prevents the unintentional supply of electrical energy from the generator into a subnetwork disconnected from the rest of the distribution grid (islanding), thereby offering additional protection to the measures specified in DIN VDE 0105-100 (VDE 0105-100), 6.2 to
– operating staff, against voltage in the disconnected subnetwork
– equipment, against inadmissible voltages and frequencies
– consumers, against inadmissible voltages and frequencies
– equipment, against the feed of faults by the generator.
In a nutshell, when the power poles go down, the inverters lose connectivity to the grid, sense this automatically, and shut themselves off.
Never mind the fact that grid-tied solar power doesn’t work at night when you need it most, never mind the fact that during and after the storm, solar insolation is drastically reduced due to rain and cloudiness, and never mind the fact that all electrical systems, solar or otherwise, are just as susceptible to storm damage as conventional power infrastructure, there is one important point that kills the entire idea.
Assuming the solar panels aren’t ripped off the roof by the hurricane/storm, they are of absolutely no use because the grid-tie is broken, and the mandated grid-tie safety features prevent the homeowner from using the inverters to get power locally.
You’d think “experts” like Kennedy and Crane would understand this basic concept…but they probably never got any closer to a solar power system than a photo op.
Some might claim that a battery backup with an automatic transfer switch might solve the issue. But, battery systems double to cost of most solar installations, and need to be replaced about every four years on average (for lead acid batteries, the most common solution), and they need to be maintained, checked, etc, plus require significant space. Compare all that to a $699 generator available from a local hardware outlet that has none of these problems and you’d understand why that is currently the solution of choice for most homeowners that want backup power after a storm.
Hopefully people following their lead for solar systems won’t try to hack their solar power system inverter safety features in time of crisis. The first person to try defeating this safety feature after a storm may get themselves or others killed or injured, either by electrocution or fire. Hopefully the solar power industry will join me in condemning this foolishness propagated by Kennedy and Crane.
h/t to WUWT reader Charles Carmichael for the NYT story link.
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Absolutely correct Anthony. The only option would then be use batteries for storage and then you would need to convert the DC to AC for the power availability during the black out. Use life on batteries is still 3-4 years.
You might note that Mr. Crane is the president of NRG. He just might know something about this…
REPLY: You’d think that, wouldn’t you? How many CEO’s can actually understand the engineering? See my reply to Brian Jay below.
Also, do you really think Robert F. Kennedy and Crane do any hands on work/engineering so they’d understand this if in fact they have solar on their own homes? Looks to me more like Crane is pushing business in the guise of an op-ed. Must be “big solar” 😉 – Anthony
Look I don’t really worry about Kennedy electrocuting himself or the whole clan for that matter, but as an Electrial Engineer I would suggest that some way around this could be found so that if you produce it locally you should be able to use it locally. The problem to me is the same if you had a diesel powered generator in that before connecting to the grid you have to sync the freqency and the voltage output in order to make sure that you are a generator and not a load. In other words you don’t have to supply everyone else in the street should the pylons come down, just your freezer.
REPLY: you and I can manage these things, but how about Joe Blow, homeowner under stress? Do you really trust people to be able to figure out how to connect/disconnect safely, or to evaluate if their solar system is damaged? First injury/fatality kills the idea, and I doubt any company wants the risk – Anthony
“When our power industry is unable to perform its most basic mission of supplying safe, affordable and reliable power, we need to ask whether it is really sensible to run the 21st century by using an antiquated and vulnerable system of copper wires and wooden poles.”
Complete hyperbole.
During NORMAL or REGULAR conditions, the electric companies do an incredibly fantastic job.
“When our power industry is unable to perform its most basic mission of supplying safe, affordable and reliable power,”
Well guess what, “green energy” will guarantee that situation.
Very interesting, thanks for the explanation. I was driving by a house with a couple large solar panels on the roof the other day. They must have been there for a while because they didn’t look like yours, the glass was all milky not black like yours. I wondered how much power they would generate at this point.
As I understand it though, as long as you’re not tied to the grid your solar is usable locally. It just has to be hooked up to your house in a way similar to a generator would be so you can ‘switch over,’ the drawback being you’re pulling from the grid with the solar as a backup only system.
This is not a Joe Blow homeowner issue. These power systems are designed to generate onto an operating grid. When the grid goes down so does the power system. Other systems are designed to operate off-grid. No connection, no risk. But now people are suggesting to spend $25,000 on a home energy system because once every 50 years they will lose power for a week? It would make more sense to give people vacation vouchers and station the national guard in affected neighborhoods to prevent looting.
The simplest way to reduce the seriousness of a post-storm crisis is to force the gas stations to have a power backup plan so they can pump fuel or replenish and a method of payment tranasction so they can sell it. Not having fuel for your car means you can’t get anywhere so you’re stuck in a house without power.
More proof that one can spend their lives around a technology and know nothing.
Careers? I hope these morons get paid what they are worth.
Another example of the Peter Principle at work and these two are poster children for the whole Green Philosophy.I really wish they had a coherent philosophy.
Don’t overlook the adrenaline factor of working in the dark while people are complaining about the loss of power.
Even smart EE’s can make really big misteaks.
Even trained EMT personnel sometimes end up measuring their own heart rate instead of the client riding the gurney in the ambulance…
Some of what you say is correct, some is not. You have to have an outside disconnect on your system for both the grid and the panels per my electrical inspector and the NEC code. However, there are inverters that are made by folks like Outback that do grid-tie but do not need to be connected to the grid to generate electricity for local use. When the grid goes down, they pull power from a battery bank/solar panels and put out AC from their inverter port(s). Property installed, the folks on the grid side are not exposed to anything hazardous. The inverter only feeds back to the grid when the grid is within its specifications and the panels are generating more than the load on the inverter side. These, however, are not the cheap setups that are frequently flogged. Those setups usually take power from the panels at 400+ volts (roughly 15-20 panels in a string) and then grid tie with no battery. Those systems will not do anything worthwhile when the grid is down or the sun does not shine.
Proper design of the panel mounting so that they do not get ripped off the roof is a must. I designed my system to withstand 130 mph winds in MA. Anchoring the mounting is neither cheap nor easy. You are talking major stainless steel lag bolts into substantial fir beams to anchor the tracking.
You can partially power your own house and reduce your electricity bills with the correct type of grid-tie system, but beyond that all bets are off.
Pity that the article was entered as an op-ed; there is no opportunity for the nonsense to be rebutted in the NYT. (This kind of nonsense persists because it cannot be so refuted.)
In addition to what has already been observed, if damage to the assemblage of all those wires up on all those “pitch pine poles” is the part of the electrical generation & delivery system that overwhelmingly causes outages resulting from storms, then, even if every roof generated (excess) PV power “so that they deliver power when the grid fails,” how is that power going to be distributed? The lines are down!
Plus, if Crane & Kennedy are really so concerned about the cost of homeowners having their own “expensive” generators, just wait till they see the cost of even modest PV systems – or is the US Treasury’s tooth fairy going to pay for all that silicon and its installation? (And living in the local EconoLodge for a few weeks is also “expensive,” assuming you can find a room.)
Lastly, they make a sneering reference to an assumed profit motive of investor-owned power companies, suggesting that those companies are really concerned about diminished profits due to power not bought by homeowners. Even if homeowners could afford to cover the entity of their roofs with PV systems, the power that they could generate would not come close to what they would normally consume, especially with air conditioners or radiant heat going, nor would not buying the equivalent power from the local utility appreciably affect the utility since industrial and public users would still be buying. Further, investor-owned utilities operate as regulated monopolies, which means their investments and rates are regulated by the regions/communities they serve, which diminishes a profit motive.
Good grief. And one of the authors is supposed to be an industry expert?
I’ve read about systems that do the same thing for solar that they do for home generators — they disconnect the house from the grid when the power goes out. They don’t disable the house, but isolate it. Is that incorrect? I don’t see anything in the quoted code at odds with what I’ve read previously.
REPLY: When the grid AC power goes off, the inverters turn off, and thus no AC power is generated nor available. – Anthony
“Electricity-producing photovoltaic panels installed on houses, on the roofs of warehouses and big box stores and over parking lots can be wired so that they deliver power when the grid fails.”
Anthony, I think you’re making a mountain out of a mole hill. There’s nothing false about the statement. It isn’t a technical manuscript just a point of information – “can be wired”. They aren’t describing how to do that and certainly aren’t suggesting the homeowner do it. Most people are smart enough to leave power wiring to professionals and the ones that aren’t can be left to Darwin…
As to safety why not just add a disconnect to the converter/meter panel(s) that interrupts both ways?
REPLY:Point: “Electricity-producing photovoltaic panels installed on houses” seems to clearly imply homeowner to me. OK let’s assume the local big box store/warehouse has live solar power, with the power pole infrastructure wrecked, how do you propose to get that power out to the neighborhood? – Anthony
Lithium cells, so au courant, do have limited life time and limited use time. A lead-acid cell’s life is theoretically unlimited with intelligent use/maintenance.
Nuclear submarines still use 126 1200# lead-acid cells per battery. They also use diesel powered emergency generators, and trained personnel
Anthony,
Wind speed, therefore wind energy as a function of hour-of-day is available. Sun intensity, therefore sun energy as a function of hour a day is also available. Demand as a function of hour of day is available and so is the existing grid supply.
It seems to me that power grid mavins or interests woould have plotted this out already as a routine power engineering exercise.
Here is such a curve from the netherlands:
http://www.clepair.net/fotos/Udocurtail201205-2.gif
and the UK:
http://windbyte.co.uk/ims/windpower/ng_winter0910_wind_demand.jpg
solar supply vs demand in AU:
http://www.solarquotes.com.au/images/winter_electric_demand_nsw_sml.jpg
This is fairly simply math if you have the data at your disposal. I suggest that this is a known ans well understood problem. Has anyone you know of plotted it? I have a feeling the reality is that wind is unreliable against demand, as is sun and the grid cannot shunt power to accomidate shifting supply and demand.
Do you have a study on hand?
When I first looked into getting solar pv, I thought it might be useful in the event of a power outage, only to discover that it wouldn’t for the reasons you state. Systems not linked to the grid are available but as David Larsen notes you then need a battery system which can be expensive and needs replacing every so often. You also lose the main financial advantage of not getting any feed-in tariff. I have wondered if a system is feasible whereby,in the event of an outage, an extra isolator could cut off the system from the grid(safe-guarding those working on it) and allowing the pv unit to work as a stand-alone. It would need to be idiot proof, as you know how clever those idiots can be. Sods law says that any power cut would be at night so the return on investment might not be too good. In the meantime I get my Fit from my panels, and keep a battery charged for back-up lighting.
Is this the same Kennedy who nixed off shore windmills because they blocked the view from his beach front property, his harbor, and other properties? Or was that a different Kennedy?
I read the standard as requiring a disconnect between the home generation and the utility service, not a requirement to shutdown the home generation system as you are implying. Of course, if the home generation system cannot meet the home’s load requirements, then it would naturally disconnect due to overload.
REPLY: That’s true, but if the home system wiring is damaged by the storm (a highly likely scenario) do you really want to risk burning down what’s left of your home by turning on your solar power system? People make generators work because those bypass the home electrical system. Direct plugs. Now I suppose if manufacturers offered a direct plug system for grid-tied inverters, it would be equivalent to a generator. I’ve yet to see one. – Anthony
@”I designed my system”: and your time to return investment is how long, how much longer than your lifetime? A good cost for electricity (less infrastructure costs) is ~6¢/kWh.
Power Generation and delivery to load is similar to the UPS Delivery Company problem. A package can come from anywhere and the package can end up anywhere, yet they do it everyday very well.
Seems to me that the UPS pick-up and delivery math model (which is quite a feat) should be adaptable to a chaotic wind/sun/coal/nuke power apportioning model.
I don’t expect it to resolve the supply/demand imbalance, but it could express the enormous demands on delivery system required.
Considering the output of roof mounted panels, what would you realistically be able to use power wise in your home assuming that the proper switches and fail safes are dealt with..Would some equipment falter if an errant cloud sauntered by?
I haven’t seen the UPS delivery math model. Is it similar to calculate how many people it takes to produce a pencil and get it on the shelf at the Dollar store?
Ceramic Fuel Cells: “The first marketed product of the company is “BlueGen” a solid oxide fuel cell which creates electricity and heat by passing natural gas over ceramic fuel cells. BlueGen is 85% efficient” It comes as a box, about the size of a small washing machine.
I thought this was a great idea, So about 3 years ago I bought shares in the company. Sadly my shares are now worth 75% less of what I paid. Looks like another fail to me. Shame really, as it is a great idea.
Diesel and gasoline generators have governors and voltage regulators or inherently stable winding designs to allow stable independent operation. PV solar systems have no stability so they rely batteries or a grid connection to stabilise voltage. Without batteries, when load is less than output, voltage will rise out of control. When load is greater than supply voltage will drop. Either case causes damage or failure of operation. That is why your system has no isolated system option. It will not work that way.
In Australia the standard installations for solar are as stated, off grid with battery storage or on grid. The latter behaves as you say; no voltage on the grid means the solar power stops. Even a power interruption will shut down the solar system, which then takes some time to reconnect.
You can buy a system which involves another meter/circuit breaker. This does the disconnection when the grid goes down, isolating the house circuit from the grid (safety for linesmen etc.). Your solar system can continue supply (during daytime) and storage/backup is supplied by a ‘chemical’ battery i.e. one which circulates ionic fluid (usually vanadium base).
I looked briefly at it, very briefly when I saw the cost. Still, if you are interested and have a spare $100,000… but still useless if your house is damaged.