Researchers have been underestimating the cost of wind and solar

How should electricity from wind turbines and solar panels be evaluated? Should it be evaluated as if these devices are stand-alone devices? Or do these devices provide electricity that is of such low quality, because of its intermittency and other factors, that we should recognize the need for supporting services associated with actually putting the electricity on the grid? This question comes up in many types of evaluations, including Levelized Cost of Energy (LCOE), Energy Return on Energy Invested (EROI), Life Cycle Analysis (LCA), and Energy Payback Period (EPP).

I recently gave a talk called The Problem of Properly Evaluating Intermittent Renewable Resources (PDF) at a BioPhysical Economics Conference in Montana. As many of you know, this is the group that is concerned about Energy Returned on Energy Invested (EROI). As you might guess, my conclusion is that the current methodology is quite misleading. Wind and solar are not really stand-alone devices when it comes to providing the kind of electricity that is needed by the grid. Grid operators, utilities, and backup electricity providers must provide hidden subsidies to make the system really work.

This problem is currently not being recognized by any of the groups evaluating wind and solar, using techniques such as LCOE, EROI, LCA, and EPP. As a result, published results suggest that wind and solar are much more beneficial than they really are. The distortion affects both pricing and the amount of supposed CO2 savings.

One of the questions that came up at the conference was, “Is this distortion actually important when only a small amount of intermittent electricity is added to the grid?” For that reason, I have included discussion of this issue as well. My conclusion is that the problem of intermittency and the pricing distortions it causes is important, even at low grid penetrations. There may be some cases where intermittent renewables are helpful additions without buffering (especially when the current fuel is oil, and wind or solar can help reduce fuel usage), but there are likely to be many other instances where the costs involved greatly exceed the benefits gained. We need to be doing much more thoughtful analyses of costs and benefits in particular situations to understand exactly where intermittent resources might be helpful.

A big part of our problem is that we are dealing with variables that are “not independent.” If we add subsidized wind and solar, that act, by itself, changes the needed pricing for all of the other types of electricity. The price per kWh of supporting types of electricity needs to rise, because their EROIs fall as they are used in a less efficient manner. This same problem affects all of the other pricing approaches as well, including LCOE. Thus, our current pricing approaches make intermittent wind and solar look much more beneficial than they really are.

A clear workaround for this non-independence problem is to look primarily at the cost (in terms of EROI or LCOE) in which wind and solar are part of overall “packages” that produce grid-quality electricity, at the locations where they are needed. If we can find solutions on this basis, there would seem to be much more of a chance that wind and solar could be ramped up to a significant share of total electricity. The “problem” is that there is a lower bound on an acceptable EROI (probably 10:1, but possibly as low as 3:1 based on the work of Charles Hall). This is somewhat equivalent to an upper bound on the affordable cost of electricity using LCOE.

This means that if we really expect to scale wind and solar, we probably need to be creating packages of grid-quality electricity (wind or solar, supplemented by various devices to create grid quality electricity) at an acceptably high EROI. This is very similar to a requirement that wind or solar energy, including all of the necessary adjustments to bring them to grid quality, be available at a suitably low dollar cost–probably not too different from today’s wholesale cost of electricity. EROI theory would strongly suggest that energy costs for an economy cannot rise dramatically, without a huge problem for the economy. Hiding rising energy costs with government subsidies cannot fix this problem. Continue reading

The “Wind and Solar Will Save Us” Delusion

The “Wind and Solar Will Save Us” story is based on a long list of misunderstandings and apples to oranges comparisons. Somehow, people seem to believe that our economy of 7.5 billion people can get along with a very short list of energy supplies. This short list will not include fossil fuels. Some would exclude nuclear, as well. Without these energy types, we find ourselves with a short list of types of energy — what BP calls Hydroelectric, Geobiomass (geothermal, wood, wood waste, and other miscellaneous types; also liquid fuels from plants), Wind, and Solar.

Unfortunately, a transition to such a short list of fuels can’t really work. These are a few of the problems we encounter:

[1] Wind and solar are making extremely slow progress in helping the world move away from fossil fuel dependence.

In 2015, fossil fuels accounted for 86% of the world’s energy consumption, and nuclear added another 4%, based on data from BP Statistical Review of World Energy. Thus, the world’s “preferred fuels” made up only 10% of the total. Wind and solar together accounted for a little less than 2% of world energy consumption.

Figure 1. World energy consumption based on data from BP 2016 Statistical Review of World Energy.

Figure 1. World energy consumption based on data from BP 2016 Statistical Review of World Energy.

Our progress in getting away from fossil fuels has not been very fast, either. Going back to 1985, fossil fuels made up 89% of the total, and wind and solar were both insignificant. As indicated above, fossil fuels today comprise 86% of total energy consumption. Thus, in 30 years, we have managed to reduce fossil fuel consumption by 3% (=89% – 86%). Growth in wind and solar contributed 2% of this 3% reduction. At the rate of a 3% reduction every 30 years (or 1% reduction every ten years), it will take 860 years, or until the year 2877 to completely eliminate the use of fossil fuels. And the “improvement” made to date was made with huge subsidies for wind and solar.

Figure 2. World electricity generation by source, based on BP 2016 Statistical Review of World Energy.

Figure 2. World electricity generation by source based on BP 2016 Statistical Review of World Energy.

The situation is a little less bad when looking at the electricity portion alone (Figure 2). In this case, wind amounts to 3.5% of electricity generated in 2015, and solar amounts to 1.1%, making a total of 4.6%. Fossil fuels account for “only” 66% of the total, so this portion seems to be the place where changes can be made. But replacing all fossil fuels, or all fossil fuels plus nuclear, with preferred fuels seems impossible.

[2] Grid electricity is probably the least sustainable form of energy we have.

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EROEI Calculations for Solar PV Are Misleading

The Energy Returned on Energy Invested (EROEI) concept is very frequently used in energy studies. In fact, many readers seem to think, “Of course, EROEI is what we should be looking at when comparing different types of energy. What else is important?” Unfortunately, the closer to the discussions of researchers a person gets, the more problems a person discovers. People who work with EROEI regularly say, “EROEI is a tool, but it is a blunt tool. An EROEI of 100 is good compared to an EROEI of 10. For small differences, it is not so clear.”

Because of the idiosyncrasies of how EROEI works, different researchers using EROEI analyses come to very different conclusions. This issue has recently come up in two different solar PV analyses. One author used EROEI analysis to justify scaling up of solar PV. Another author published an article in Nature Communications that claims, “A break-even between the cumulative disadvantages and benefits of photovoltaics, for both energy use and greenhouse gas emissions, occurs between 1997 and 2018, depending on photovoltaic performance and model uncertainties.”

Other EROEI researchers with whom I correspond don’t agree with these conclusions. They recognize that in complex situations, EROEI analyses cannot cover everything. Somehow, the user needs to be informed enough to realize that these omissions result in biases. Researchers need to work around these biases when coming to conclusions. They themselves do it (or try to); why can’t everyone else?

The underlying problem with EROEI calculations is that EROEI is based on a very simple model. The model works passably well in simple situations, but it was not designed to handle the complexities of intermittent renewables, such as wind and solar PV. Indirect costs, and costs that are hard to measure, tend to get left out. The result is a serious bias that tends to make the EROEIs of solar PV (as well as other intermittent energy sources, such as wind) appear far more favorable than they would be, if a level playing field were used. In fact, published EROEIs for solar PV (and wind) might be called misleading. This issue also exists for other similar calculations, such as Life Cycle Analyses and Energy Payback Periods.

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Intermittent Renewables Can’t Favorably Transform Grid Electricity

Many people are hoping for wind and solar PV to transform grid electricity in a favorable way. Is this really possible? Is it really feasible for intermittent renewables to generate a large share of grid electricity? The answer increasingly looks as if it is, “No, the costs are too great, and the return on investment would be way too low.” We are already encountering major grid problems, even with low penetrations of intermittent renewable electricity: US, 5.4% of 2015 electricity consumption; China, 3.9%; Germany, 19.5%; Australia, 6.6%.

In fact, I have come to the rather astounding conclusion that even if wind turbines and solar PV could be built at zero cost, it would not make sense to continue to add them to the electric grid in the absence of very much better and cheaper electricity storage than we have today. There are too many costs outside building the devices themselves. It is these secondary costs that are problematic. Also, the presence of intermittent electricity disrupts competitive prices, leading to electricity prices that are far too low for other electricity providers, including those providing electricity using nuclear or natural gas. The tiny contribution of wind and solar to grid electricity cannot make up for the loss of more traditional electricity sources due to low prices.

Leaders around the world have demanded that their countries switch to renewable energy, without ever taking a very close look at what the costs and benefits were likely to be. A few simple calculations were made, such as “Life Cycle Assessment” and “Energy Returned on Energy Invested.” These calculations miss the fact that the intermittent energy being returned is of very much lower quality than is needed to operate the electric grid. They also miss the point that timing and the cost of capital are very important, as is the impact on the pricing of other energy products. This is basically another example of a problem I wrote about earlier, Overly Simple Energy-Economy Models Give Misleading Answers.

Let’s look at some of the issues that we are encountering, as we attempt to add intermittent renewable energy to the electric grid.

Issue 1. Grid issues become a problem at low levels of intermittent electricity penetration. Continue reading

Eight Pitfalls in Evaluating Green Energy Solutions

Does the recent climate accord between US and China mean that many countries will now forge ahead with renewables and other green solutions? I think that there are more pitfalls than many realize.

Pitfall 1. Green solutions tend to push us from one set of resources that are a problem today (fossil fuels) to other resources that are likely to be problems in the longer term.  

The name of the game is “kicking the can down the road a little.” In a finite world, we are reaching many limits besides fossil fuels:

  1. Soil quality–erosion of topsoil, depleted minerals, added salt
  2. Fresh water–depletion of aquifers that only replenish over thousands of years
  3. Deforestation–cutting down trees faster than they regrow
  4. Ore quality–depletion of high quality ores, leaving us with low quality ores
  5. Extinction of other species–as we build more structures and disturb more land, we remove habitat that other species use, or pollute it
  6. Pollution–many types: CO2, heavy metals, noise, smog, fine particles, radiation, etc.
  7. Arable land per person, as population continues to rise

The danger in almost every “solution” is that we simply transfer our problems from one area to another. Growing corn for ethanol can be a problem for soil quality (erosion of topsoil), fresh water (using water from aquifers in Nebraska, Colorado). If farmers switch to no-till farming to prevent the erosion issue, then great amounts of Round Up are often used, leading to loss of lives of other species.

Encouraging use of forest products because they are renewable can lead to loss of forest cover, as more trees are made into wood chips. There can even be a roundabout reason for loss of forest cover: if high-cost renewables indirectly make citizens poorer, citizens may save money on fuel by illegally cutting down trees.

High tech goods tend to use considerable quantities of rare minerals, many of which are quite polluting if they are released into the environment where we work or live. This is a problem both for extraction and for long-term disposal.

Pitfall 2. Green solutions that use rare minerals are likely not very scalable because of quantity limits and low recycling rates.  

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