Five Solar Myths You Should Not Believe

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  • russruss Solar Expert Posts: 593 ✭✭
    Re: Five Solar Myths You Should Not Believe

    The supposed myths:
    Myth #1: Solar is only good in warm climates.
    Myth #2: You still need fossil fuel energy as a backup even after you install solar panels.
    Myth #3: Going solar means going without modern conveniences.
    Myth #4: Solar power is not ready for mass consumption.
    Myth #5: Making solar panels takes more energy than it could ever produce.

    My reply on the other site:

    This 'myth busting' is very misleading (intentionally) and not helpful at all.

    Myth 1 - In general - the closer to the equator the better. Germany has much less insolation than Spain for example - the same panel will produce far more in Spain than Germany.

    Myth 2 - Unless you have a large enough system to export more power during the day than you use in 24 hours this is not true. Same for winter - if your system is not large enough to supply all your needs with December ?nsolation you need power from the grid which is more than likely hydrocarbon based.

    Myth 3 - Having all the modern conveniences simply means a larger system.

    Myth 4 - As long as governments dish out the subsidies OK - without them it would die a quick death.

    Myth 5 - Agreed, this is a silly point you often run across that is not true

    Fact 1 - For every mW of solar PV or wind power put into the grid there needs to be 100% backup from another source- probably hydrocarbon based. Until storage (say a minimum of 72 hours) is available PV power simply screws up other suppliers on the grid. The recent spate of stories about storage systems (mostly NaS batteries) will work to assist with frequency control but 1 or 10 mW of storage on the grid is very, very little.
  • dreesdrees Solar Expert Posts: 481 ✭✭✭
    Re: Five Solar Myths You Should Not Believe
    russ wrote: »
    The recent spate of stories about storage systems (mostly NaS batteries) will work to assist with frequency control but 1 or 10 mW of storage on the grid is very, very little.
    True - but if 1 MW capacity which stores 7.2 MHw only takes up the space of 2 semi-trailers, it's not hard to see that NaS batteries distributed around the grid would go a long ways towards making intermittent renewables a lot more palatable to the grid when penetration gets high enough.

    I couldn't find any charge/discharge efficiencies of the NaS batteries - I wonder how much efficient they are...
  • BB.BB. Super Moderators, Administrators Posts: 31,048 admin
    Re: Five Solar Myths You Should Not Believe

    Wiki to the rescue:
    A sodium-sulfur battery is a type of molten metal battery[1] constructed from sodium (Na) and sulfur (S). This type of battery has a high energy density, high efficiency of charge/discharge (89–92%) and long cycle life, and is fabricated from inexpensive materials. However, because of the operating temperatures of 300 to 350 °C and the highly corrosive nature of the sodium polysulfides, such cells are primarily suitable for large-scale non-mobile applications such as grid energy storage.
    ...
    The performance of the commercial NAS battery bank is as follows:[7]
    1. Capacity : 25–250 kW per bank
    2. Efficiency of 87%
    3. Lifetime of 2,500 cycles (at 100% DOD - depth of discharge), or 4,500 cycles (at 80% DOD)

    Don't know about costs... But if electricity can be delivered today to the home in the $0.10-$0.30 per kWHr range---The costs should not add "significantly" to those costs. If electrical production costs are ~1/2 the delivered costs, then that would seem to place a cost of ~$0.5-$0.15 per kWH for stored energy to make it somewhat economical (basically, power is near "free" when in surplus--coal/nuculear plant at night, wind/solar when power is available, etc. and the batteries can now "sell power" at market rates--perhaps 2-4x that for peak demand periods?).

    -Bill
    Near San Francisco California: 3.5kWatt Grid Tied Solar power system+small backup genset
  • AntronXAntronX Solar Expert Posts: 462 ✭✭
    Re: Five Solar Myths You Should Not Believe
    russ wrote: »
    Fact 1 - For every mW of solar PV or wind power put into the grid there needs to be 100% backup from another source- probably hydrocarbon based. ...PV power simply screws up other suppliers on the grid.

    There are already gigawatts of gas turbine capacity available. When the sun shines, solar PV reduces demand from peaker gas turbine plants. They do vary their output already due to night / day power demand variability. For example, take a look at renewable daily watch document from California ISO system status page. Look at bottom graph depicting variability from thermal generating resources. It swings by about 6,000 MW.

    Now, about solar power screwing up other suppliers. They can calculate the impact to their capacity factor loss and charge PV suppliers for "backup service". The free ride that grid-tie PVers are getting, will have to end. At the same time, the free ride that CO2 emitting suppliers age getting will have to end as well. You never know, the fossil fuel burners might end up paying PV suppliers once a fee is finally placed in CO2 emissions.
  • dreesdrees Solar Expert Posts: 481 ✭✭✭
    Re: Five Solar Myths You Should Not Believe

    Around here, nightime rates are about half the daytime rates, sometimes 1/3rd - so if you can store as much wind as possible at night and shift it to the day, you can nearly double the value of that electricity.

    And if you can do that while only losing 15% of the power, from a purely economical point of view, it seems to be a no-brainer.

    From an environmental point of view, time shifting like that may or may not make sense depending on what else is supplying grid power.

    IMO, anything we can do to reduce coal powered energy is the way to go - in a lot of areas where wind can power a very high percentage of demand, adding these batteries to "smooth out" the wind power would allow more wind power to be used.

    Adding these batteries may also be cheaper than adding additional transmission capabilities if you situate a wind farm where the grid capacity is marginal and would let you avoid throwing away power frequently.

    Lots of possibilities...
  • dreesdrees Solar Expert Posts: 481 ✭✭✭
    Re: Five Solar Myths You Should Not Believe

    [QUOTE=AntronX;62891For example, take a look at renewable daily watch document from California ISO system status page. Look at bottom graph depicting variability from thermal generating resources. It swings by about 6,000 MW. [/QUOTE]
    I can't wait to see the renewable charts after they get that 1.5GW of wind added to the grid over the next couple years. :) Should double CA's wind generation - the first electrons will start flowing early next year.

    Looks like an additional 4.8GW of solar (concentrating and thin-film PV) are in the works - will be interesting to see how much of that will actually get built.

    Even with all that generation, it will only get us a fraction of the way there in terms of renewable power...
  • WindsunWindsun Solar Expert Posts: 1,164 ✭✭
    Re: Five Solar Myths You Should Not Believe

    That "myth buster" factoid has been around for a while in various forms, but it still misses the point, and also is heavy on the strawman arguments - setting up false scenarious so it can shoot them down.

    For grid tie systems one big advantage of solar is that produces max power about when the peak demand is, reducing the need for peak power standby generators eventually.

    There is no way - unless some fantastic new energy storage tech comes a long - that solar will ever supply probably more than 10-25% of power usage, but it can (or could) reduce peak power demand from fossil fuel plants considerably.
  • nielniel Solar Expert Posts: 10,300 ✭✭✭✭
    Re: Five Solar Myths You Should Not Believe
    russ wrote: »
    The supposed myths:
    Myth #1: Solar is only good in warm climates.
    Myth #2: You still need fossil fuel energy as a backup even after you install solar panels.
    Myth #3: Going solar means going without modern conveniences.
    Myth #4: Solar power is not ready for mass consumption.
    Myth #5: Making solar panels takes more energy than it could ever produce.

    My reply on the other site:

    This 'myth busting' is very misleading (intentionally) and not helpful at all.

    Myth 1 - In general - the closer to the equator the better. Germany has much less insolation than Spain for example - the same panel will produce far more in Spain than Germany.

    Myth 2 - Unless you have a large enough system to export more power during the day than you use in 24 hours this is not true. Same for winter - if your system is not large enough to supply all your needs with December ?nsolation you need power from the grid which is more than likely hydrocarbon based.

    Myth 3 - Having all the modern conveniences simply means a larger system.

    Myth 4 - As long as governments dish out the subsidies OK - without them it would die a quick death.

    Myth 5 - Agreed, this is a silly point you often run across that is not true

    Fact 1 - For every mW of solar PV or wind power put into the grid there needs to be 100% backup from another source- probably hydrocarbon based. Until storage (say a minimum of 72 hours) is available PV power simply screws up other suppliers on the grid. The recent spate of stories about storage systems (mostly NaS batteries) will work to assist with frequency control but 1 or 10 mW of storage on the grid is very, very little.

    1> solar is only good where the sun shines.
    2> not true if you install an off grid system large enough, but costs and room for such a large system comes into play sometimes making one compromise the larger system they would've wanted. we often do advocate some kind of backup power when the possibility of the system not supplying all of the power needs exists.
    3> no, not true at all. for a gt system it means all or part of the power is offset by the pvs and you can still run what you want to. for off grid this is a no-brainer as otherwise there might not have been any power at all or, in the case of a generator, then no power without a noisy generator running at times. we do advocate conservation with or without solar, but that may only equate to shorter times or more efficient items to be run so there is no need to do without.
    i should also mention that there is so little renewable energy being sent to the grid, and much of this is also deliberately held back by the utilities, that it is impossible to say renewables are messing up the utilities in any way and the few % of solar capacity online is not going to help the daytime surge demand very much and can and should be allowed to be expanded upon. don't forget utilities are monopolies that look upon renewables as an infringement to their territory and control of it with some actually believing they won't be making as much profit by allowing renewables online..
    4> sure it is if manufacturers can meet the demand. the problem is that most people really don't give a crap where their power comes from and they don't want to take the time to do this themselves let alone be bothered. they just take the time to complain about what they already have to pay in bills.
    another point here is that the solar industry will not die if incentives go away as the industry existed before incentives were thought of even when pvs were at $10/w. it may slow down a bit as the purpose of incentives is to increase the numbers of installs and propel a good and needed industry that is doing something in a positive direction.
    for the record i don't see the reasoning behind raising the costs of fossil fuels as this will not result in that many more going to solar. the real problem is that many people don't have that much money to put into it to begin with. the ones that it will force to go solar are those that can already afford it and will just switch to the cheaper option, but the majority will not be able to make that switch without lots of help. it is available to some people in some states, but is not always that good of a program or is non-existent. even when reimbursed it may take a long time to get it so one still needs a vast sum of money up front. add to this that many now are joining the ranks of the lower class due to the economy and fewer jobs and you will just make things worse with forcing higher rates.
    5> maybe, but who cares for that same person complaining has tvs, coffee makers , washer and dryer, computers, and a whole host of items that consume electricity and contribute nothing to the production of it. shall they forego all of their electric things because they don't contribute? i'd see them pointing a gun at me if i tried to take those power consuming things from them so who are they to criticize any efforts we make?
  • russruss Solar Expert Posts: 593 ✭✭
    Re: Five Solar Myths You Should Not Believe

    I was just reading an article about LiS batteries from Sion Power. They were used in the solar plane that recently set records.

    From the Sion web site:
    Performance targets for this program are to exceed 500 Wh/kg and 500 cycles at commercially viable recharge rates. By 2016, the goal is to produce a cell with 600 Wh/kg and 1,000 cycles.

    Seems they are not there yet but maybe it will come.
  • russruss Solar Expert Posts: 593 ✭✭
    Re: Five Solar Myths You Should Not Believe

    Solar would not die without subsidies/incentives but the number of systems sold would drop by maybe 90% and a lot of companies would definitely disappear.

    The leasing companies would run away so fast they could set world sprint records.
  • icarusicarus Solar Expert Posts: 5,400 ✭✭✭✭
    Re: Five Solar Myths You Should Not Believe

    A couple of simple comments

    Plug in hybrids and EV can (and I predict) will be able to provide a considerable storage for PV in the future. Remember, just as PV can spin a meter backwards, so can a plug in car, buying when the price is cheap (due to excess capacity) selling back when it is expensive (peak load). It has the capacity to reduce the idle spinning capacity of the grid considerably. That said, EV/PEVs will add a load to the grid net/net, but that will free up fossil fuels for other uses.

    Second, with judicious use, a Pv powered house (with a good size array) can produce enough power for the average family. The biggest trick it to use that power efficiently, something we tend not to do because the power is cheap.

    Third. PV could complete if the playing field were truly level visa vis subsidies. Most other energy choices come with substantial subsidies, and coal in particular, if it were required to pay it's environmental costs going in would be way more expensive at the meter than it is. Trying to compete with $.10 kwh coal fired generation without having to pay it's environmental cost makes it tough for $.30 kwh PV. Same for Nuke power, if we priced it at it true cost, PV becomes "competitive"

    Fourth, as someone else pointed out, Pv works great where ever there is substantial sun. Even At 50 degrees north, my system powers our house better in the short winter days than it does in the summer, due to low PV temps, as well as a significant boost from reflection off of the snow.

    Fifth, as for Pv becoming "mainstream" what it takes is a commitment as public policy to fund energy sources that are sustainable. Even if PV installed today is "more expensive" today, the rising price of energy will make it more competitive over it's live cycle. If we are serious about solving the energy/environmental issues that confront us as a society we really have to look at the total cost of our energy choices. As long as we have artificially cheap energy, we will not make much progress. For example, after spending a month in the UK this spring, and paying ~$8 per gallon for gasoline, you realize that you don't see a lot of Hummers on the road. If we had to pay $1 kwh we would get smart about how we use it (as a society)

    Tony
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