Dairy farmer installs solar in Goodhue County: An interview with Peter Reese

Peter Reese of Goodhue County is a dairy farmer and entrepreneur that started Perpetual Harvest, LLC to help Minnesota dairy farmers become energy-independent and decrease energy costs.

Through conducting local site assessments, using strategic energy efficiency and renewable energy technologies, and convening the necessary technical assistance, Peter strives to empower farmers with ownership of their energy futures. Brittney Bray with CERTs recently interviewed Peter about the solar thermal water-heating project he implemented on Reese Family Dairy Farm.

Brittney Bray: What got you interested in this project?

Peter Reese: My family has always been interested in energy savings and renewable energy. When we were kids, my parents actively researched practical DIY ideas and would take us to see passive solar in-ground homes and other renewable energy solutions between milkings. When several companies approached the Goodhue community a few years back to gauge interest for commercial-scale wind projects, my brother Paul and I looked at the contracts and ran the numbers. We realized that investments in efficiency and solar thermal hot water would pay back quicker and be a good fit for us. Dairy farms are an ideal venue for solar thermal hot water just like hotels, laundromats, restaurants and any other business that uses a regular, predictable hot water demand 24/7/365. I did my research on farm energy consumption, bought The Energy Detective (TED) to analyze the farm’s load and discovered that, yes, after the milking vacuum pump and the bulk tank cooler, the electric hot water heater used the most electricity. Variable speed vacuum pumps pay back well only when you’re milking all the time like a big farm and my father had already installed a thermal energy recovery system to capture the cows’ heat from the milk. So…the tank for the solar system just had to be installed and plumbed in line with the existing hot water supply and Voila! (there was more to it than that, trust me).

Brittney: Who was your installer and where did the solar thermal panels come from?

Peter: James Darabi of Solar Farm installed the panels made in Alexandria, MN by Solar Skies. We wanted everything to be manufactured in Minnesota or at least the US. Unfortunately, since we seem to be a little behind the rest of the world, we had to get many of our components—most notably the Caleffi pump station guts—from Italy. They work great, but I know Midwest workers know how to machine good quality equipment in Minnesota small towns and cities, we just need entrepreneurs to help make it happen.

Brittney: What have been the results?

Peter: The system works great. Before, Paul had to strategically wash the pipelines and milk equipment to make sure the hot water had time to recharge. Now he strategically washes only to maximize solar gain and sometimes to test the system to see if it’s possible to run out of hot water (it isn’t). James also designed it properly so that even during the longest, sunniest days of the year it will not overheat. This experience has also helped us realize even more clearly that there are many other low-hanging (and even quicker pay-back) prizes to be had such as tuning up pumps, fixing refrigerators, milking during the daylight when possible to avoid burning lights, and so on. I plan to do a statistical analysis of before and after utility bills to see what the actual benefits are to the pocketbook (I say I’m waiting for a full year of data, but I might be procrastinating).

Brittney: Do you have any suggestions for a dairy farmer interested in starting a similar project?

Peter: If at all possible, DO NOT install the system in the winter. We started by trenching in a fifty foot SolarFlex line during the first snow of last winter and first watched the tank temperature climb during the last snowfall (yes, it works without direct sunlight). Most importantly, however, document your energy habits and consumption and know your business needs. It is likely that an investment of between $10,000 and $20,000 in a solar thermal hot water system will provide a good return (better than a car, for sure), but your farm may be better off installing an in-line plate milk cooler (to directly heat your water up while pre-cooling the milk) or a variable speed vacuum pump (if you milk for many hours during the day). It just depends on your operation. The bottom line, however, is: for zero cost, a couple behavior and habit changes can very likely reduce waste, lower the electric bill, and improve your farm’s operation instantly.

Learn more about Reese’s efforts in a case study from CERTs:
Dairy Farm Entrepreneur Installs Solar Thermal and Builds Community.


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