Like many of us at the Co-op, I am very interested in the energy challenges facing our world. While I have read a lot about the subject, I am not a scientist, just an interested layman. On April 19 of this year, I sat down with Greg Pedrick, long-time member-owner at Honest Weight.
Greg has worked since 2005 with the New York State Energy Research and Development Authority (NYSERDA) in research and development, and currently serves as a Project Manager with the Renewable Energy Opportunities group, under the Technical Business Innovation (TBI) division. Greg’s primary work is focused on energy storage and promoting meaningful demonstration and product development projects to grow this active market. With his diverse technical background, he also contributes to several other TBI focus areas, including power systems and mass transit transportation.
Greg previously worked for Vermont Energy Investment Corporation, Radiometrics, Cold Regions Research Laboratory and Bechtel Power Corporation, expanding his electrical systems and power background. He holds a Bachelor of Science in Electrical and Computer Engineering from Clarkson University (1986), and a Master of Science from Dartmouth College (1997).
For me, ours was an enlightening conversation. Because of his background, Greg is familiar with and well conversant in the advantages and problems of solar energy. I had never looked at our energy sources from the perspective of our power grid. From that vantage point, our power choices are not so simple. Here is a transcript from my interview with Greg:
Bob: I am a big fan of solar energy because it doesn’t add to climate change. I know there are a lot of forces fighting against its implementation. Can you explain to me why we just can’t replace our current energy sources with solar farms and panels on our homes?
Greg: Let me first give a brief explanation of how solar works. Solar energy is produced when solar cells are activated by the sun. The sun on these cells stimulates current, which can then be used as an energy source. What many people don’t understand is that the current produced by solar is DC, or direct current. Since our grid uses AC, or alternating current, all current from solar generation has to be transformed from DC to AC current, with the concurrent loss of energy and expense, before it can be transmitted on the grid. We could convert the grid to DC but that wouldn’t be practical. We have an old, established power grid that is constantly in use. It would be difficult and prohibitively expensive to change it. Besides, the problem with DC current, as Thomas Edison discovered when he tried to sell it as our future power source, is that it doesn’t travel very far over transmission lines. So, all solar power has to be transformed to AC to be used by our grid.
Bob: That’s something I didn’t know. Why can’t we just store that energy that solar produces and then use it when we need it?
Greg: Another problem with solar energy is one of timing. If you think about it, the maximum output for solar energy occurs between 11 AM to 3 PM every day, when the sun’s light is strongest and most direct in North America. But that’s not when we need it most—at least for our homes. For residential uses, the maximum need for energy output is between 7 to 9 AM and 5 to 9 PM, when most people are home, using their lights and appliances, cooking, reading, and whatnot. It’s kind of a mismatch, like two people who can’t seem to work things out because one is a morning person and the other person is a night owl. On the other hand, solar has a good potential for powering commercial buildings like Honest Weight. Commercial buildings are more compatible with solar than residential buildings; commercial buildings’ energy needs coincide somewhat with the times for the maximum output for solar energy.
Bob: Back to the grid. Can we somehow transfer solar to where it’s needed at the times of peak solar generation?
Greg: The power in the grid must be carefully balanced, and when solar is generating at maximum capacity, that causes imbalances in the grid. That is a limitation in our present grid, one that is difficult to fix at the present time. Right now, the grid cannot accept all the output from solar at one time. Solar can also be an unreliable energy source. The amount of solar energy produced depends on whether the day is sunny or cloudy, and rain or snow also hinders solar power. The amount of available sun, or kilowatt-hours per square meter per day, expressed as kWh/m2/day for your mathematical readers, is how a solar panel’s energy output is rated. This varies widely.
Bob: I’m getting depressed. You’ve given me lots of reasons why solar energy—the power source of the future—isn’t all it’s cut out to be. I don’t know if that’s a fair assessment. After all, solar farms are popping up like mad all over the state. Also, people are putting solar panels on their roofs. Is this a scam? What gives?
Greg: Not at all. I’m just pointing out some of the problems with solar that are often overlooked by people who see it as a panacea and instant cure for our energy problems. Solar energy has been growing at a tremendous pace, not just in this country but all over the world. This growth has produced technical innovations which have reduced the price for production of solar energy. Also, the supply of such things as solar panels has increased exponentially, and that, too, has reduced the cost for solar energy. That’s why, for instance, there’s a sudden boom in solar farms and solar companies. Solar, after all, except for some of the pollution caused by the mining of materials for solar panels, does not add to global warming. All I’m saying is that there are still a lot of issues to work out, until solar energy can really replace the predominant forms of energy that we use today—oil, coal, gas, etc.—which do add to climate change. One of the best things about solar is that it has raised public awareness of the potential of other energy sources like geothermal and wind, that do not contribute to global warming.
Bob: You’ve worked in the nuclear industry. Nuclear doesn’t add to climate change, but it has a lot of other problems. What are your thoughts on that source of energy, especially in light of the potential shut down of Indian Point?
Greg: Because I worked in the industry, I am aware that I might have some bias towards it, and you and many others might not like what I’m about to say, but I think that nuclear power has its advantages and shouldn’t be dismissed. For one thing, there’s no need to transform the energy produced by nuclear power plants to AC power. Like energy produced by coal, natural gas, or hydro, the power produced by nuclear fission is made from steam, that rotates a turbine producing AC energy. Nuclear power plants are built right on the grid, and most of the present plants in operation have been paid for. Furthermore, the capacity factor of nuclear power, once it is up and running, is 100 percent. Compare that with solar’s capacity factor, which is only about 15 percent.
Bob: Aren’t you overlooking a few problems, like what do you do with the radioactive materials and the old nuclear facilities that are no longer useful? How about Fukushima and Chernobyl? That’s quite a bill we’re leaving for future generations.
Greg: Well, there certainly is a negative perception that’s been created by what I see as some isolated incidents. Nuclear power plants have in general a high safety record. But there definitely are problems with nuclear power. At this point, it takes a long time to build new plants. It has been so long since a new plant has been built in this country, that some of the suppliers that you would need to build the parts for the plants are no longer in business. Another problem, which is fundamental, is that containment is very expensive. Also, you need a source of electrical energy to shut a plant down in an emergency. Sometimes that energy can only be produced by safety backups, that is, diesel generator sets, known in the business as ‘diesel gen sets.’ And if that resource isn’t functioning, all safety backups are jeopardized.
Bob: That sounds pretty scary to me. Is that the problem they had at Fukushima and Chernobyl?
Greg: Yes, that was part of the problem. At Fukushima the diesel gen-sets were under water and could not supply power to keep the cooling water circulating, so it took a very long time to shut the plant down. Another issue with nuclear is that only 4 percent of the fuel in a fuel rod is burned during the fission process (relevant to light water reactors), and that leaves a lot of waste to dispose of. That’s an obvious problem and has to be considered as far as the overall cost of nuclear energy. But, then again, nuclear has a high level of output power, especially compared to solar, and it doesn’t add to climate change. Right now, we’d have a hard time replacing the energy that it does provide. Fusion (heavy water reaction) would be a much better energy source than fission, but not much money is going into research for fusion these days.
Bob: Thanks for enlightening me and our readers about this topic. I’d like to continue our discussion about energy and the grid. I’m sure we’ll get some feedback to this article, which is a good thing. We all need to know more so that we can be part of the solution to our energy problems.
On a closing note, Greg has been an HWFC member-owner since 2005. He lives in the northern Adirondacks in a timber-frame house he designed and had built by a neighbor and friend. He practices conservation and “simple living” in everyday activities. His goal is to consume less, and have a lighter impact on the planet. He enjoys all outdoor activities, his Golden Retriever, whom he calls his ‘best pal,’ and local food and libations. Although he is an electrical engineer by training, he takes it as a compliment when, as someone once said to him, “But you don’t act like an engineer!” We at the Voice are fortunate to have Greg as an integral part of our awesome Web team.