Monday, January 5, 2015

Both Low EROEI and Low Power Density is a Serious Problem - Solar PV Addition

Taking information from two sources I'm going to show that a combination of low EROEI, and low power density is a huge problem.   Here is the first source which talks about EROEI with energy storage.  It's called catch 22 of energy storage.  Here is the second that talk about power density among other thing.  It's called Sustainable Energy — without the hot air.  Both of them are a good reads if you haven't read them already. 

From the First Source

The EROEI for solar pv with energy storage is listed at 1.6.

From the Second Source

If we covered 5% of the UK with 10%-efficient panels, we’d have

10% × 100 W/m2 × 200 m2 per person = 50 kWh/day/person. (page 41)

The red stack (i.e. energy consumption) in figure 18.1 adds up to 195 kWh per day per person (page 103).

Now lets think about this a little

EROEI describes the energy that is needed to be invested (i.e. used) in order to get more energy. If the EROEI is 2 then one unit (of some unit of energy) invested will get you 2 (of that unit). If solar is to become a permanent thing then maintaining any given area of it will take energy. The amount of energy is determined by it's EROEI. Lets say that the EROEI is 2. Then maintaining 1m2 of it would take 1/2m2. That 1/2m2 would need 1/4m2 and so on. The sum of all these works out to some finite number.   In order to work it out you need something called the Geometric series.

Here's the equation where X = EROEI

Using the formula I get 2.67(1/(1-(1/x))) using solar PV's EROEI. The number 2.67 is a multiplier we can use to figure out the total area needed.  That means instead of 5% of the uk's land providing 50 kWh/day/person it would take 13.3 % (5 X 2.67 = 13.3) when taking EROEI into account.   In order to get 195 kWh/day/person it would take 51.87 % (13.3 X (195/50)) or 207,480 m2 per person.

That doesn't even count the area of land used by the energy storage.  Pump hydro for the source given.   Here's a good source that talks about that.  Guess what it take a lot of space, and don't forget that there are other land uses as well. 

Source Two Page 41

And don't think you can do without most of the storage because of demand response, management, whatever you want to call it.   Solar power manufacturing facilities cost a lot.  In order to keep the prices down they need to be run 24/7, so at most you can only ration 37.5 % (1 / 2.67 = 37.5) percent of that power. 

This is simply madness, or more like a fantasy.  It's time people came to terms that they have two choices.  Fossil fuel, or nuclear power.   Fossil fuel's give us a few short years in exchange for our climate and our children's future while nuclear power gives us hope and a better life for countless millions.   I know which one I'm rooting for. 

Update:  I changed a lot.  Credit to my brother Jeremy for helping me with the math.  I also added another post that talks about the same thing for wind.


  1. You leave out the obvious. Nuclear is too expensive. That's why half of Europe is phasing out while the other half is forced to do so.

    Leaves us with the obvious. We take all power sources in account, leave out fossil fuels...keep the nuclear option in the basket for a moment.
    Then we do an hour by hour real world study. This has been done 10 years ago (renewables got cheaper till than). We end up with a paneuropean supergrid, 80% wind and 20% other renewables. 4.65€c/kWh (wind is even cheaper nowadays.).
    PV only the installed capacity and what gets installed because it is cheaper behind the meter. No additional storage needed. No additional hydro needed.
    All financing accounted for.

    Read the study by Gregor Czisch.

    The KiteGen is also ready in a few month. It's Stem version got an EROEI of 150 while the Carousell configuration will boost that to 1400.
    Not that EROEI matters with technology that easily gets past 10.
    PV is actually around 6-30 month payback time depending on location and technology. Take 50 years runtime and do the math.

    Why would you limit your 100% one source scenario to PV anyways?
    And remember that technology is no finite fuel source.

    One more.

    1. Your claims about costs look wildly optimistic. Here is the 2014 ECOFYS report on European electricity costs and subsidies

      Median LCOE of on-shore wind is about 80 EUR/MWh. Nuclear comes in at around 90-95 EUR/MWh. However as has been repeatedly pointed out LCOE is not a full measure of costs. Intermittency causes extra system level costs.

      All other renewables (except hydro) are more expensive than nuclear. Unfortunately hard coal and gas (run at maximum achievable load factor) remain cheaper than anything except hydro.

  2. Did the studies you site take energy storage, energy needed for a supper grid and other necessary energy inputs into account? If they don't they are incomplete. My main criticism of EROEI is that it is often incomplete and overstated as a consequence. I'll read your studies if you link to them someplace that doesn't have a pay wall. I don't believe nuclear is more expensive then renewable, and in nuclear is to expensive to do I wont start supporting renewable because I don't think they can work. I'd just give up all hope I have for the future. At any rate I wrote another post to respond to your comment.

    Also, please read these two as well.

    1. Nothing hidden, all accounted for.
      The Czisch study also takes into account financing besides storage.
      and the study.
      the link to the English translation on wikipedia is dead...
      You could asl Czisch for a copy.

      A new study based on the green-x model.

      Why would it be relevant what we believe?
      This is physics.and economics. You need evidence to back up your believes.

      Is there a complete study on a nuclear grid? I don't think so.

    2. It isn't relevant to the universe what we believe, but it's very relevant to our behavioural. If you want me to support renewable you have to convince me.

      Sometimes need for evidence goes both ways. Bother 100% renewable is feasible, and 100% renewable isn't feasible, are positive statements that require evidence. In my articles I've provided you with some evidence that you haven't really addressed yet.

      Over the last 4 years read many different studies and reports by both sides, and I've become more an more convince that 100% renewable wont work. I'll read the green-x model as well. In turn why don't you read this study that compares nuclear versus renewable grid (and other) costs.

  3. Research needs to continue for solar, wind, storage and (especially) advanced nuclear. I could care less for the LWR which Alvin got fired for advocating against (in favor for MSR) because a Carlington (solar flare) event could render them meltdown prone.
    If solar does continue its price decrease and if batteries continue their price decrease, and if wind continues its price decrease (via larger turbines?), then these will contribute to fossil free in areas where nuclear power is unwanted or unjustified cost wise.
    For sure, we need to concentrate on the best reactor design, which is Transatomic's molten salt reactor that only requires 1.8% fissile for startup!