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How Much Electricity Consumption Is Too Little?

Energy efficiency world views collide.

There are two dueling, strongly held, views on the definition of energy efficiency. The idea of energy efficiency, at least to economists, is to overcome market failures that can lead to people consuming energy even when the full societal costs of the energy exceed their benefits. An alternative perspective also pervades policy circles. This perspective appears to be that people should just use less energy, period. To economists, this view is a perversion of the notion of energy efficiency. Energy efficiency should be about the efficient use of energy, not the non-use of energy.

One policy arena where these dueling views are colliding is electricity rate design. About a month ago I participated in a workshop at SMUD concerning a proposal to add a monthly fixed surcharge to homes that newly add rooftop solar. The logic behind the proposal was a familiar one to readers of this blog site: many fixed utility distribution costs are recovered in variable, per kWh rates, and solar homes avoid paying for those fixed costs when they generate their own electricity but stay connected to the system. For SMUD, this is a financial concern: how to equitably recover the fixed costs of their infrastructure? But there is a larger societal issue that gets overlooked when we focus too much on just the financial viability of a distribution utility. The larger question is: exactly what kind of behavior do we want to discourage, or encourage, from consumers when we set electricity prices, and why?

LightBulbDollarSign                                              Source:

The SMUD proposal was, not surprisingly, roundly criticized and opposed by solar trade groups. Somewhat frustrating, but not surprising, was the vocal opposition from and other environmental groups as well. My frustration stems from my belief that we have a much better chance at combating climate change if we direct our scarce resources away from rooftop solar toward more cost-effective solutions like grid-scale solar. What was surprising to me, however, was how the conversation turned to the wisdom, even the ethics, of SMUD’s general tariff structure, which has a higher monthly fixed charge, and lower variable prices, than most other California utilities.

Electricity Prices: How High is Too High?

The general tone of this part of the discussion was that it was socially irresponsible for SMUD to charge a lower variable price of electricity, because it would encourage people to use more electricity. The argument is often extended to support steeply rising increasing-block rate structures, such as exist in much of California, on the grounds that higher prices encourage conservation (i.e., discourage electricity use). This begs a question that I wish I had asked at the time, but didn’t. If lower electricity prices are “bad”, and by implication higher electricity prices “good”, then how high is too high?

Economists have a framework for answering this question. It is called marginal cost. Because we, as a society, are worried about climate change and other environmental costs, we should include those in marginal cost as well. That’s called social marginal cost (the cost of producing the electricity plus the external damages done by it). Ideally marginal prices would be set at social marginal cost, so that when a consumer turns on a light bulb, or charges their electric vehicle, the incremental amount they pay matches the incremental cost they impose on society.

In a previous blog, Severin Borenstein talked about work we have been doing estimating the social marginal cost of electricity around the US, and comparing it to the marginal ($/kWh) price faced by residential customers. These social costs reflect the marginal wholesale cost of electricity and researchers’ estimates of the environmental costs of generation. There is a striking diversity across the US in the relationship between marginal prices and social marginal cost, but one fact that stands out is that marginal prices in California are among the highest in the country even though our marginal cost of electricity is among the cheapest and cleanest in the country.


Energy Efficiency: Dueling Definitions

Again, the idea of energy efficiency—at least as an economic concept—is to overcome market failures that lead to people consuming energy even when the costs exceeded their benefits. There are two types of market failures, broadly speaking: either the energy price is “wrong” or the price is right but consumers don’t respond correctly to it.

The first failure is usually linked to externalities, like climate change, whose costs may not appear in the energy price, leading consumers to consume “too much” because the price, lacking the environmental cost, is “too low.” The second failure can be attributed to a myriad of institutional breakdowns, like landlords who don’t have an incentive to invest in efficiency for tenants, or behavioral factors such as consumers misunderstanding or not wanting to spend the time understanding their electricity prices.

But a corollary to the economic view of energy efficiency is that if true social costs are low, it’s OK to consume more. In fact, it’s a bad idea, even wasteful, to devote scarce resources to reducing consumption if the costs of those investments exceed the benefits provided. This is where electricity pricing comes into the picture. If we set electricity prices well above the costs of serving customers, we are encouraging consumers to take steps to reduce electricity consumption when the electricity cost savings outweigh the investment costs to the customer, but not to society. Rational consumers will reduce their electricity consumption (or install rooftop solar) based upon these price distortions. Indeed, this is exactly what my colleagues at UC Davis, Kevin Novan and Aaron Smith find in their 2016 paper, The Incentive to Over-invest in Energy Efficiency. They study air conditioner replacements in Sacramento and estimate that while the AC investments save about $11.50 per month in avoided social costs, they save the consumers who make the investments about $26.50 per month because of SMUD’s rate structure where marginal prices exceed marginal social cost.

Considering the fact that marginal electricity prices are more than double the marginal cost of energy (including externalities) in much of California, any behavioral reluctance on the part of consumers to invest in energy efficiency could actually improve rather than reduce total benefits. The customer’s cost-benefit test for saving money needs to be passed by a wide margin before energy efficiency makes economic sense in places like California. Unfortunately, as the above map illustrates, as a country, we are devoting funds to overcoming customer inertia in all the wrong places. Energy efficiency program expenditures are highest in states with high prices and clean electricity and low to non-existent in the states where electricity is dirty and more expensive.

Energy Efficiency Program Expenditures per Customer by State



Less is more, no matter what?

One can argue with the specific numbers, but the general principle of marginal cost pricing is pretty compelling. If consumers want to consume energy and are willing to pay the societal cost to provide it, their consumption creates a benefit that economists call welfare. If prices rise well above social marginal cost, then we are inefficiently discouraging the use of electricity. Yet there are some who are not persuaded. They appear to think people should use less energy, period, regardless of whether costs are low or costs are high.

The inconsistency in the “less is more, no matter what” view of energy efficiency is becoming more obvious as the grid gets cleaner and we are hoping to electrify other sectors, like transportation and home heating. The former trend means that the social marginal cost is getting cheaper, even while the total cost of providing electricity is getting more expensive (including fixed costs like renewable capacity, the transmission system, etc.). In fact, there are times and places where electricity is effectively costless. Do we really want to discourage consumption, even the charging of EVs, through high prices during times like these?

It is interesting that some opponents of rate structures like monthly fixed charges also support increased time-varying prices. Support for the latter implies a recognition that when costs are low it’s OK to encourage consumption. However, opposition to fixed charges when marginal prices are so far in excess of costs implies a rejection of the same principles of marginal cost pricing that would lead one to favor time varying prices.

The other area where the view of “less electricity is better” runs into trouble is when we consider what the alternatives to electricity consumption are. Those alternatives are increasingly gasoline or natural gas. If marginal electricity is clean and cheap, we want people to shift from gasoline to electricity to power transportation. But high electricity prices clearly undermine that transition.

So, what exactly are we trying to achieve with electricity prices? Once we deviate from the principle of marginal cost pricing, we risk making moral judgments about how other people perceive the benefits of consuming energy. Now I’m not against doing that. I quite enjoy judging other people, in fact. But it’s a wobbly foundation to base public policy upon.

As a policy community we need to come to some common understanding about what energy efficiency is and should be. This means recognizing that consuming energy is not, in and of itself, a bad thing. Many fantastic goods and services are made and enjoyed using energy. What is “bad” is wasting money and polluting the environment. Energy efficiency efforts should be focused on truly wasteful, inefficient consumption. When we place the marginal price of electricity excessively high, we are throwing out the good consumption with the bad and making the achievement of our ultimate goal of a prosperous, clean-energy society harder to reach.

Keep up with Energy Institute blogs, research, and events on Twitter @energyathaas.

Suggested citation: Bushnell, James. “How Much Electricity Consumption Is Too Little?” Energy Institute Blog, UC Berkeley, June 3, 2019,

26 thoughts on “How Much Electricity Consumption Is Too Little? Leave a comment

  1. True! No savings is too little. If you consider saving even 10 watts and if thousands of people do it, the savings could be huge. And these are very small numbers. all of us together can contribute so much more to this. We personally use a power monitoring device by Ohm Assistant ( to measure our power consumption. It helps us to detect which devices are faulty and where power leakages are happening.

  2. I found it frustrating that under the EV (electric vehicle) rate, partial peak rates extend from 7:00 AM to 2:00 PM and, starting at 2:00 in the afternoon, electricity cost 48 cents per kilowatt hour in the summer. Nearly always, net demand is extremely this time. During a portion of it, renewable electricity was curtailed (wastted) to cope with the low demand rather than sell it to EV owners at a reasonable rate.

    Instead of charging my car during daylight hours, I charged it at 11:00 PM when net demand was much higher but my rate was only one half to one quarter as much. Ironically, the EV rate is suppose to be environmentally sensitive and economically efficient. However, for people on the EV rate, it is problematic during much of the day.

    This is just an example of the absurdity of some California rates. I shouldn’t pick on California. Similar problems can be found in other parts of the country that have time-of-use rates.

    Thankfully, California rates have gradually moved in the direction. of lower daytime rates. EV 2 replaced EV with low rates that extend until 3:00 PM. This is a big improvement. Nevertheless, there is still room for improvement.

  3. You’re overlooking the effect fixed charges have on AVERAGE electricity price, which is actually what most people look at, after the bottom line of their bill that is. A large constant fixed charge applied equally to all customers means “small” customers pay more per kWh than “big” ones, where small and big can be determined by some pretty arbitrary factors, e.g. family size. Should small families pay more for their electricity? For all customers, but much more powerfully at low usage levels, lowering consumption raises price. Calcs I made a couple of years ago of PG&E’s tariff for us in Berkeley showed at just above 80 kWh/mo, where I am, isn’t too bad, about 23 ¢/kWh . But, I wouldn’t want to lower my usage much further! A net metered customer who uses just 1 kWh/mo would be paying north of $1 for it. You might think this is a good way to recover fixed costs, but I don’t. The megagrid isn’t an exclusive club. All costs should be recovered in accurate time and spatially varying prices. It’s the only defensible tariff. If this means consumption is too low from the economist’s perspective, and virtuous low-carbon footprint customers pay little, so be it. This is preferable to punishing small users whatever their motivation, small family, low income, obsessive efficiency buffs, whatever. We are so far below full social cost pricing, does it actually matter that some might be consuming too little? Don’t forget over consumption of electricity also means over consumption of appliances, building wiring, etc.

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