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This kind of thing is actually a real problem from a grid stability point of view. The unpredictability of wind and solar and the lack of a way to store their

• brc 12y ago
  It's also a long term capital investment problem. Power generation is hugely capital intensive, and there are disincentives for investing in such a volatile market. However, the demand is nowhere near as volatile as the supply can be, and you can't keep power as inventory, so it's anyones guess how this all plays out. Certainly we can't become reliant on solar/wind supply as this would be disastrous. One thing is for sure, we need to level the playing field and remove all subsidies and regulations so that cost effective power can be reliably created. I fear the direction we are going right now is in the complete opposite of how things should be going.
  • D_Alex 12y ago
    >you can't keep power as inventory Well, you can, you need batteries or suchlike. One of the most interesting effects of adoption of electric cars could be that their batteries could be used as energy banks, charging when power is cheap and feeding power back to shave peaks off the demand. Also... Let's build a battery gigafactory in Australia!!
    • waps 12y ago
      Batteries are ~30% efficient. Sending power to end users is ~85-90% efficient (though less, of course, if there's overcapacity, and then it drops very fast). So let's say you'd get 30% * 85% ^ 2 ~= 20% efficiency out of it. If you're talking Australia. Outside of CBDs, why would you so much as bother with a grid connection at all ? Solar panels + a solar boiler + in-house batteries will probably be about as reliable as grid power in Australia. Plus it'd be truly distributed. What we need is a Solarcity company in Australia. (Or, Australia has uranium mines ... why not go nuclear ? Fuel is free)
      • D_Alex 12y ago
        >Batteries are ~30% efficient Citation needed. Lowest claim I recall is "better than 85%". Also, I support nuclear power for Australia. It makes so much sense in a politically and geologically stable location, with plenty of empty spaces. Own fuel supply is icing on cake.
        • spacefight 12y ago
          "politically and geologically" That might not be the case for the runtime of the nuclear power plant. Think 40y ahead. I can't.
  • lotsofmangos 12y ago
    If you removed all subsidies, the situation would change less than you might think. The biggest difference would be nuclear going out of the game. Solar right now is competitive on retail price of electricity, which is all you need for rooftop solar to make sense.
  • eikenberry 12y ago
    > you can't keep power as inventory Sure you can. Using compressed air, springs, pumped water and other such simple techniques. It just takes additional investments that haven't been worth it. Maybe this is changing.
    • PeterisP 12y ago
      None of these things work at a reasonable enough scale. You can't put a gigawatthour in compressed air or springs; pumped hydro is a possibility if you have a huge enough suitable reservoir. If we'd want to have all our energy coming from renewable resources, then you'd need stations a hundred times bigger (or a hundred times more) than the current pumped hydro reservoirs, and creating them would be an ecological nightmare, most likely requiring a destruction of a major river or lake for each such station.
      • vidarh 12y ago
        Tianhuangping Pumped Storage Power Station has a 13GW/h storage capacity and about 2GW generating capacity, using two 6.8 million m^3 reservoirs - one artificial, and one built on the Daxi Creek, separated by about 900m of pipes (but I believe the vertical drop is about 600m). (if you're curious, that adds up to about 1/7500th of the worldwide average usage in 2008) If you assume 50m high structures (the lower dam is actually 72m), the area required for each reservoir is "only" 136,000 m^2. With only 20m tall structures, you need about 340,000 m^2 That's within range of the largest buildings (e.g. Boeing's largest factory has a surface area of about 400,000 m^2, and a volume of 13,3 million m^3; Tesla's factory covers an area of about 510,000 m^2). Of course this is assuming you can find somewhere suitable to give you a 600m drop, or water volume required grows quickly. But the system could be mostly closed to reduce the need to be straight on a major river. And in Japan there's pumped storage plant with a 250,000m^3 pool 500m below ground, so clearly it does not need to be a matter of building one of the reservoirs 600m up a mountain side like with Tianhuangping. To the extent the ecological risk is massive, it's because it's presumably far cheaper to pick a suitable river and dam it than having to build two fully artificial reservoirs.
      • ZeroGravitas 12y ago
  • crdoconnor 12y ago
    >Power generation is hugely capital intensive, and there are disincentives for investing in such a volatile market. Only nuclear power is outrageously capital intensive. Solar and wind are much, much less capital intensive. >Certainly we can't become reliant on solar/wind supply as this would be disastrous. Oh yea, running fully on renewable energy would be terrible :/
    • vixin 12y ago
      It's terrible at night when there's no wind and during the day when there's cloud cover and no wind. So you run the capital intensive parallel generators - and that's called running fully on renewable, is it?
      • crdoconnor 12y ago
        >It's terrible at night when there's no wind Maybe you could look up the last date when there was no wind across the whole of the continental US at the same time? >when there's cloud cover One of the biggest myths about solar panels is that they do not work when it is cloudy. They still produce power under clouds - not as much as a sunny day, but a LOT more than you'd expect. http://pureenergies.com/us/home-solar/solar-basics/solar-myths/ http://pureenergies.com/us/home-solar/solar-basics/solar-myt... >So you run the capital intensive parallel generators - and that's called running fully on renewable, is it? Renewable energy already is transported between countries to handle different levels of load / production (Germany already exports it to France pretty frequently when it's sunny in Germany). I assume this would continue to handle the different levels of sun, wind and load in various locations both nationally, across state borders and internationally. Who knows though, maybe one day the whole world will go dark and windless at the same time?
    • jacquesm 12y ago
      > Only nuclear power is outrageously capital intensive. Solar and wind are much, much less capital intensive. The way to look at capital in this respect is to look at $/W of installed power. So even if in absolute numbers you don't require a huge amount of $ to put a solar plant into production versus putting a (small) nuclear plant into production the capital costs are still considerable when you compare apples with apples. Also, nuclear scales better in this respect than solar. So capital costs are not per-se the best way to compare solar, wind and nuclear. Endless volumes have been written about this, one of the biggest benefits in my opinion is that solar and wind put fewer apples into many more baskets which should - if properly implemented, which currently they are not - in theory result in a more resilient power infrastructure.
  • asgard1024 12y ago
    > However, the demand is nowhere near as volatile as the supply can be, and you can't keep power as inventory, so it's anyones guess how this all plays out. Certainly we can't become reliant on solar/wind supply as this would be disastrous. This is bullshit. Our civilization has done this for thousands of years, in a different area - food. This is just a return to different mode of operation with regards to energy, but it's not really economically impossible.
• lotsofmangos 12y ago
  "This becomes a strong disincentive for the construction and operation of these plants that are vital for steady, dependable electricity supply." They are only vital if there is not enough storage. If it is a disincentive to build new base-load generation due to the change in the market, doesn't that mean that the money is going to funnel more into storage, given there is unlikely to be a reduction in overall energy investment? Also, storage is a buy low sell high business that depends on owning suitable real estate, which makes it look pretty attractive in markets where the price sometimes goes negative. Anyone with a big flow battery, or even a decent hill with a bit of railway up it, could have done quite well there.
  • tanzam75 12y ago
    Storage is very tough to work out. You pay for all this capacity, but you only get to make money a couple of times a day. Dam a river and you can generate power 24 hours a day. Build a pumped-storage facility, and you'll be lucky to get a half-hour out of it. You really need a wide spread between baseload and peak prices to make it work out. Ironically, renewables are destroying the economics of pumped storage in Germany. On sunny days, solar panels displace much of the peak load from pumped storage. On rainy days, the pumped storage suddenly becomes crucial to the grid. Except that pumped storage cannot make money by operating only on rainy days.
    • lotsofmangos 12y ago
      Presumably it can make money be operating every night though, which is where it would end up if solar expands to the level where it replaces conventional generation.
• jessaustin 12y ago
  I heard an exec from Green Mountain on a radio program a few weeks ago (unfortunately this doesn't seem available without extortionate fees: http://www.humanmedia.org/catalog/program.php?products_id=293 http://www.humanmedia.org/catalog/program.php?products_id=29... ), and she claimed that the power sold back to the grid had enabled them to delay and/or avoid capital improvements. That is, power produced near where it's used doesn't have to travel as far. She portrayed the "disincentive" as a good thing.
  • tanzam75 12y ago
    That's a very narrow way of looking at the problem. It isn't as simple as that. Our electric infrastructure is sized for the peak load. All the power plants, the transmission lines, the substations, the transformers, etc. To the extent that renewable energy can displace peak load, it does reduce the need to upgrade the grid. Thus, a west-facing solar panel can be good for the grid. Because peak load is usually at sunset, the solar panel feeds power into the grid just when it needs it. (A south-facing solar panel maxes out at solar noon, so it doesn't coincide with peak load.) However, this only works if the power source can be counted on absolutely reliably, each day, every day. What if it sometimes rains at sunset? Then all the infrastructure still needs to be sized for the peak load anyway, as though the solar generation didn't exist. But when the sun shines, all that investment is just sitting there doing nothing, not earning any money. You have the same capital costs, but you're now amortizing it over fewer kilowatt-hours. At least solar panels produce next to no power at night, during baseload. Wind doesn't have this nice property.
    • jessaustin 12y ago
      I wrote three sentences; there was bound to be some simplification. The current regime reinforces a number of assumptions about how humans use electricity. One of those is, as you note, that the infrastructure must be built to handle "peak power". The more insidious twin assumption to that one is that "peak power" is a number that falls out of heaven. Both of these assumptions, although largely true in the recent past, are slowly losing their validity. If everyone in my neighborhood installs solar and wind, and as a result the damned power company pulls some accounting tricks and bribes the PUC into raising rates, except the consumer groups whine so they compromise by moving to variable spot rates communicated minute-to-minute (which would certainly help out the power storage businesses mooted elsewhere in this thread), and as a result I have to buy new appliances and HVAC equipment that can intelligently figure out when to draw power, sure... I'll complain, because I'm a cheap bastard. But life will go on.
• Retric 12y ago
  Base load power is something of a misnomer. You can easily design a nuclear / coal power-plant that goes from 60-90% capacity vary quickly. The issue is that lowers efficiency, both when operating outside the normal range, worse simply having that capacity also lowers peak efficiency. In the end it's a trade-off from a more flexible grid vs more flexible power-plants. Granted, most coal/nuclear power plants are not currently designed to be flexible for these reasons and they take a while do a cold start vs simply changing output within a fixed range.
• artsrc 12y ago
  > operation of these plants that are vital for steady, dependable electricity supply Maybe. http://theconversation.com/baseload-power-is-a-myth-even-intermittent-renewables-will-work-13210 http://theconversation.com/baseload-power-is-a-myth-even-int...
  • coryrc 12y ago
    There don't appear to be any engineers involved in those predictions. Their predictions require many other changes: "The baseload issue can be solved by reducing baseload demand,having some renewable energy sources that can supply baseload power and increasing the proportion of flexible peakload plant in the generating mix." Who should pay for this? Price pollution properly, and you will see the push away from natural gas and coal to nuclear, not "renewables" at far higher prices ($7-10 billion AUD/year for Australia, according to this article). In summary, if you change the goalposts (reduce baseload) and pay lots more, "renewables" are totally doable according to somebody with no engineering experience.
    • brc 12y ago
      'reducing base load demand' Who is putting their hand up for their street lights to be switched off? For their hospital to run expensive co-generation when there isn't enough supply or it becomes to expensive? A lot of these statements are made by groups which just pretend that you can cut down a lot of energy and that's how they make their sums work. The BZE group do this with their calculations and it's pretty unrealistic. The problem I have with all of these plans is that they drastically inflate the cost of energy for no real reason apart from dislike of certain generation types.
• crdoconnor 12y ago
  >This becomes a strong disincentive for the construction and operation of these plants that are vital for steady, dependable electricity supply. The market structure in addition to the regulatory environment in the U.S. (e.g. requiring utilities to purchase all provided wind energy at higher than natural market price) are both part of the problem. The main disincentive to invest in the grid is the fact that it is a monopoly and like all monopolies the owner's incentives are to slash investment and milk the monopoly under ALL circumstances. Comcast behaves in a similar manner. The rules whereby grids are forced to buy wind energy or only allowed to make a certain level of profit are simply hacks to prevent the monopoly from becoming too abusive. There is absolutely no reason why a grid should be privatized and this is the core problem with them in America. Ironically, this profiteering has led to outrageously high electricity prices in some areas that has also led to rooftop solar being such a good deal (while the feed in tariff still exists anyhow).
  • tanzam75 12y ago
    > The main disincentive to invest in the grid is the fact that it is a monopoly and like all monopolies the owner's incentives are to slash investment and milk the monopoly under ALL circumstances. Quite the opposite, in fact. In most of the PJM states, power generation is deregulated and market-driven, while the grid itself remains a regulated monopoly. Regulated monopolies operate under a fixed rate-of-return. They would much rather spend $6 billion and earn 10%, instead of spending $5 billion and earning 10%. That's what happens when the rate of return is fixed. The more they spend, the more they earn. Consumer groups routinely show up at regulatory commissions and complain that the electric utility is spending too much on upgrading the grid. > Comcast behaves in a similar manner. Comcast is a minimally-regulated monopoly that is not earning a fixed rate of return. The less they spend, the more they earn.
• ajcarpy2005 12y ago
  I figure that the eventual evolution of relatively high-energy home appliances towards being able to vary their power draw depending effectively upon real environmental factors outside (sun/wind/tidal/geothermal) will make a lot of the discrepancies between power demand and availability go away. Additionally, homes and communities need to invest in thermal mass technologies/infrastructure. Also...now that I think of it, data centers use enormous amounts of power so I wonder if Internet-users could be financially (or otherwise) incentivized to use certain software or SaaS platforms for batching their effective data bandwidth and downloading content at times when the energy demand is low but output or potential clean energy output is high. This could actually probably make a pretty big difference.