Slashdot Mirror
The Myth of Going Off the Power Grid
Lasrick writes: Dawn Stover uses Elon Musk's announcement that Tesla will soon be unveiling plans for a battery that could power your home as a starting point to explore the idea that "going off the grid" is going to solve climate change. "The kind of in-house energy storage he is proposing could help make renewables a bigger part of the global supply. But headlines announcing that a Tesla battery 'could take your home off the grid' spread misconceptions about what it takes to be self-sufficient — and stop global warming." Stover worries that shifting responsibility for solutions to climate change from governments to individuals creates an 'every-man-for-himself' culture that actually works against energy solutions and does little to reduce overall greenhouse gas emissions. Instead, "smart grid" technology would be much more efficient: "With a smarter grid, excess electricity generated by solar panels and wind turbines could be distributed to a network of on-the-grid home and car batteries. Some utilities have also experimented with using home water heaters as an economical substitute for batteries."
"Putting energy in a battery throws away 30% to 40% right off the top in charge and discharge inefficiencies as shown above. If you have access to the grid, it makes no economical sense to give that up! Energy storage in the grid is 100% efficient and virtually unlimited whereas storing energy in batteries is limited and not only throws away 30% of your energy, but also:"
Source: http://www.aprs.org/off-grid-maybe.html
This seems to be an article more about condemning Tesla's batteries that about energy. In fact the word "watt" appears nowhere. Before you can have a discussion about energy you need to be armed with some facts about actual energy needs and potentials. This is just more anti-Tesla propaganda.
As well as anti-reality.
"Stover worries that shifting responsibility for solutions to climate change from governments to individuals creates an 'every-man-for-himself' culture that actually works against energy solutions and does little to reduce overall greenhouse gas emissions."
Right - because central planning is a much better idea <eye roll>.
The bottom line is that when I reduce my carbon footprint I save money, at least in the long run. I've invested hundreds of dollars in the last year in getting LED lights throughout the house. I'll make that money back within 5 years - I can already see the difference on my light bills. Next year I'm hoping to start my solar farm on my very large southern-facing roof. I'll likely have negative light bills when I'm done and it'll pay for itself within 3 or 4 years (yes, that's less than average and there's a reason for that having to do with my air conditioning and the solar panels taking heat off the house).
So, yeah, we need the grid upgraded. But at this stage we need a lot of people trying a lot of different things so that we can find out what works and what's economical. Ultimately, if it doesn't save me money it ain't gonna happen.
Do you have ESP?
Some utilities have also experimented with using home water heaters as an economical substitute for batteries
Many large buildings used to make ice overnight when the electricity rates are low (in some parts) and melt the ice to cool the building during day time reducing the load on the air conditioner. Such techniques would be effective if the electricity rates vary. Like the old long distance plans, having a peak and off-peak pricing alone would encourage the consumers to schedule their washing machines and dishwashers during the off-peak hours.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
I have a 10 KW, grid tied battery backed up system in an all electric house. Everything except my deep well pump, washer/dryer, hot water, range and geothermal compressor are connected on the critical loads panel. Generally over the last 5 years or so, the system produces more power than used with the rest going to charging the batteries and powering the grid. However, there has only been a few times over the last several years that system has produced more than consumed from the grid. I estimate that I would need 30-50 kw to power everything. However, the geothermal compressor draws perhaps 5 kw for 4-5 minutes at a time and cycles several times an hour. Since the geothermal system works mostly at night or if we went off grid, the storage capacity of the battery backup would have to be increased substantially from the 16 KWH that we have now since the compressor would deplete the batteries in a few hours. None the less our electric bill is down at least 80% from pre-PV days.
"Gentlemen, you can't fight in here! This is the War Room!" -- Dr. Strangelove
Why would they? The grid has no inherent storage capability into which to dump your day-time excess energy. It costs the power company to manage your bit of excess you're trying to dump into the grid.
A few days ago I saw a nice graph showing PG&E's averaged output power during a typical 24h. It's a slanted U-shape, with the bottom somewhere around noon, then a sharp increase between 6PM and 9PM, tapering off after midnight and dropping slightly after 7AM. If they took away the solar-generated power fed into the grid by individual installations, the U becomes much deeper and PG&E projected that it will get deeper in the near future.
The HUGE problem this energy generation/consumption pattern creates is that the baseline generators must provide the bottom of the U and not a Joule more. Everything else, especially the evening spike, must come from coal and NG power plants. Since in time the ratio between the peak and the baseline increases, more dirty and greenhouse gas emitting power plants MUST BE BUILT. In fact, all these 3 to 5kW solar installations make the greenhouse gas situation worse if the excess energy is not stored, which is contrary the feel-good but incorrect assumption about how all these solar panels help save the planet.
I have been living off the grid since 1997 with a solar powered system. The power is converted to AC with an 8000 watt inverter for my home and excess power is stored in a lead acid battery bank. My system wasn't purchased as complete but was built up for an approximate 5 year period until I could be completely self sufficient. I do have to use a gasoline generator to charge the battery bank when the sun doesn't shine for a few days. Other alternatives need to be developed to supplement solar for that very reason. The problem with the grid tie system is the power companies will never allow you to earn any income from your sale of the electrical product. They derate the price so that you will never get a payment from them. You could get an almost zero bill but it will never come out with you making anything. I never connected to the grid so I wouldn't become lazy and not complete my system. I know of the utility company's plan from others who have a grid tie system or have called them to ask of their approach to solar power returns. The greatest expense is the batteries. I am now going on my third set of expensive deep cycle batteries to keep my stuff going. A better battery would be so great. The Edison or Ni Fe battery sounds like the ideal approach to getting a reliable type that requires little maintenance. I haven't researched the Tesla battery yet but I am glad someone is at least doing something instead of just complaining. I am getting older now and the lead acid batteries are too heavy to just lug around for the changes after a few years of use. I value my independence and hear from my neighbors how they lost power during a storm when they needed it the most. I know this isn't the way for everyone but for those who are willing to try to breakaway from the socialist system of being hooked up for life this is the only way to go for now.
I've been fortunate enough to live entirely (100%) off-grid for several years now. When I went to build my house we quickly determined that it wasn't worth it to have power brought back to the house site (I'm 5 miles up in the mountains) and after looking at wind for a bit I went with a solar setup. It's been an interesting experience, and reading the article I can't really say I agree with the author on most points.
I have a 36 panel system that theoretically can create ~40kwh/day on the average day. I have 20 batteries (used to be 24) to cover overnight and overcast/bad weather storage.
First off there's no question that I don't have anywhere near enough batteries. My solar guy used a variety of online calculators to figure out the size and needed and both underestimated my requirements and overestimated the amount of daily discharge the system could handle. As a result we bought a vastly undersized battery system (~1350AH when it was new, more like 750AH now) that we ended up discharging around 75% nearly every night. This is turn is a deadly drain on your batteries and drew down my system sharply to its current capabilities. My own back-of-the-envelope calculations show that I need a system more like 3000AH in capacity to properly power the whole house for a couple of days (if needed). My propane backup generator gets run far more than it ought right now.
Leaving that annoyance to one side though, being off-grid and responsible for my own power (and water; I have an excellent well) is nothing short of awesome! It's my power! I can do what I want, run what I want, and the only thing I have to worry about is what my supply is (when it's at night).
Mind you I've done all kinds of things to be more efficient of course. I am in an ongoing process of replacing all of my CFLs and the handful of incandescents still around with LEDs as I find LEDs that are both price-rational and workable for the task. I just replaced 42 halogen track lights with some excellent LEDs I tracked down from a company named Torchstar and that made a huge difference--I basically hadn't used those tracks at all since we built the house since they were so energy expensive. The house itself is an ICF (Insulated Concrete Form) house and very efficient (13" thick walls), with the entire house heated with radiant heat as opposed to a more typical forced air system. Over the years I've learned to take advantage of a strong sunlight day and run dishwashers and the clothes when the sun is out.
My biggest intermediate goal is to replace the battery stack with something more appropriate. There are several high-amp setups out there that I should be able to make work and I hope to do so next spring (I'm going to be driven to this anyway by the slow death of my current stack). Longer term I'd like to add even more panels until I'm up to 54, not so much for added storage (there's only so much you can put in the batteries and I should have that covered) but to increase the surface area of collection during a cloudy day (the panels will make power even in overcast, so more in that case is better). I think my inverters (two of them, 4000W each) are sized appropriately, though I'll have to add another charge controller when the new panels go in. I just built a new shed to house all of the batteries (it's also ICF) and will be rigging it with a solar heating system this summer; this will keep the batteries warm and toasty during the harsh winters. Even longer term (years), I want to enclose the upstairs deck with a greenhouse, which would help make me more self-sufficient food wise.
I wouldn't change it for the world, honestly....being utterly independent is just a different but good feeling.
If anybody has questions, just ask!
Ferret
Sic gorgiamus allos subjectatos nunc