When Can We See Solar Impact?

A little while ago California signed into law SB-1 which was labeled the “million solar roofs” legislation. That bill calls for California based utilities and policy to encourage home owners to install solar photovoltaic systems to generate power they can use but also which can be fed back to the state’s utility grid at times when the home owner makes more power than they are using at that time.

Now that sounds like a serious effort and, in fact, there is nothing else like it around the USA. But there was a similar effort started earlier in Germany and now practically everywhere you drive you in Germany you see solar panels on the roof. Such programs tend to succeed in focusing citizens to do their part in helping change the dynamics of a problem.

But how much will that really impact California’s electrical grid? Below is a picture of today’s power usage for a typical spring (not hot or cold) day – one where little air conditioning or heating is required.

CA Electrical Usage

Now this is a very typical day. In the middle of the night around 3 am you find we use the least energy and around noon to 3 or 4 pm we use the most. On this day there is a secondary peak of needed power around 9 pm at night. Guess what we are doing then – Yes, you can actually see us all watching TV.

This graph also shows how much power California has in reserve to meet unexpected needs. This is the green jagged line at the top of the graph. You can find this type of graph daily here.

Interestingly enough, a couple of days after this one we had a weekend day where there was particularly low overall demand. The weekend helps because businesses are closed. But it also helped that the weather was not too warm nor too cold and the day was “long” so that we needed less inside lights. Here is what that day looked like on the same graph –

Low Demand Day

On very hot summer days, the mid-afternoon peak will rise as high as 50 GW or more than 2x what we need at night. And on such days this demand exceeds all the power that we can generate in the state. So we have to purchase additional power from our neighbors if they have surplus.

So now you can see the point of the million roof bill. At precisely the times when California is shortest on power, the solar panels on those 1,000,000 roofs will be generating the most power … on hot sunny summer days. And if they generate about 5 KW per roof (a typical installation) then 1,000,000 roofs will generate 5 GW of power which is about 10% of all of the power required by the system. In such a case the top of the peak in the curve, will flatten off just a little bit. But that little bit is pretty important because it provides relief at just the right time.

What if we were able to have Californians put up not 1,000,000 solar roofs but instead 10,000,000 would be built over some period of time. What would be the impact then? Well then these roofs would potentially generate 50 GW of power and this would be all that the system requires. Wow. Why not set that as the target right now and help us drive towards energy independence? Great question.

Some answers have to do with the politics of it all. But some of the answers also have to do with how the overall electrical power grid will perform when so much of our power is generated from these sources. What happens if the sun goes behind a cloud in a change of weather over large parts of the state? How will that be handled, for example?

Still more relate to how will people be compensated for the power they generate. Today, you are not paid at all but you can receive credits against your electric bill and power you use at night. But if you make more power than you need, you do not get an additional compensation. So that has to be reconciled.

There are many questions like that where we will need to build up experience and make adjustments over time and based on real world learning, I suspect. So even if we could “flip the solar switch” on quickly, it is probably best if we do it at a little slower pace.

Posted in Essays, Green Perspectives

Oil and Water

In the late 1980s and early 1990s California experienced a protracted drought. This condition lasted so long that the various governments across the northern part of the state began public relations campaigns to encourage citizens to find new ways to conserve.

Some policy changes were enacted as well – toilets in new construction were required to have lower water usage, upon sale of an existing home toilets were required to be upgraded to the new home standard, shower heads for sale in California were limited to 2.5 gallons per minute (about 10 liters per minute for the rest of the world). And, of course, all of this helped.

But in the end, it was found out that there was a little problem with all of this civic mindedness. it turned out that if all of the people in CA used NO water for personal use this would save 10% of the total water used in the state. The rest went to industry and agriculture. And most of that went to agriculture.

So if you could save 10% of the agriculture it would be substantially more than if all of the citizens saved 20-30% which is quite a bit for each person!

One more point here is that water costs for personal use and for industrial use are substantially higher than for agriculture. So much so that some have compared the costs of water for agriculture versus that of other industries. In California it 1 acre-foot of water ( = 386,000 gallons or 1200 cubic meters) will produce $60 of revenue for the state if used to grow cotton or alfafa but $980,000 if used in a semiconductor factory! So the efficiency gain is 16,000x!

Now having been involved with my daughter in this exercise when she was in 3rd and 4th grade about 15 years ago, I had to think about what was really going on today in regards to oil consumption. Sounds like a pretty distant link right?

The question i asked myself – What if all of us in the USA stopped using oil today entirely or just saved 30%; such a savings would be very difficult for most of us to achieve quickly. But suppose we could do this over some short time like a few years. What would that do to the price of oil? And my conclusion is that it would have very little overall affect. Because we are increasingly a smaller part of the overall use total. China and India are growing and becomeing 1st world citizens so quickly and with such impact that their combined 2.3 billion consumers will dwarf our pun 0.3 billion citizens.

Does this mean that we should not bother to conserve, convert to solar, wind and other alternatives. No, it rather further emphasizes how important this conversion is and how deep we must take it to truly achieve real independence from the fate that awaits others who cling to the past and the inevitable price rises that still will follow.

To the extent we can not just cut back on oil consumption but really change energy consumption from oil based sources to electricity that is generated from renewable sources this can be game changing for our country and its competitiveness. Inexpensive resources are key to industrial competitiveness – for a country, a state, even a rather local region.

At the individual and family level, this means that we need to consider changing how –

  • we heat water from primarily natural gas to solar with electricity or gas providing the backup
  • we heat our homes to have more reliance on geothermal, heat pumps and solar and less on gas and oil
  • we purchase new cars with a greater emphasis on hybrid technology and the use of the electrical grid to charge batteries for shorter trips
  • we individually participate in creating more energy locally by having solar PV on our roofs
  • we understand where our energy uses are in our homes many of which can be trimmed through us just being aware and making small changes.

The ultimate impact of all of these changes (talked about endlessly elsewhwere) can be that we do not have to participate in the wars that others will fight over who gets what share of a resource that is already scarce.

But, now I am going to let you in on a secret. If you do this even yourself or with your family, you will be more competitive in comparison to your neighbors. Think about this. If you drive a Prius, combine trips, turn off lights, make some of your own energy, get off the oil addiction – then you are simply more competitive on a growing basis year by year. Gas today at $4 is not headed back to $2 … ever. We are more likely to see $6 or $10 before the end of this decade.

So put together a plan now. Find ways to really understand your energy usage and start changing it in ways that are easy but really do not change how you live. You will be surprised how easy this can be done. And every thing you save is likely to be savings that you continue to reap month after month, year after year.

Posted in Green Perspectives