Saturday, October 15, 2016

Part 4 - A Lesson on Creating Clean Energy at Home

This is the fourth in a 5-part series about how buying a diesel vehicle in 2013 resulted in an electric car and renewable solar panels on our house in 2016. 

If you'd like to read all the parts of this series, you can see them here.
Part 1 - How Volkswagen is Helping us Repay the Planet for Its Sins
Part 2 - Our Search for a Cleaner Car
Part 3 - Buying a Used 2016 Chevrolet Volt
Part 4 - A Lesson on Creating Clean Energy at Home
Part 5 - Making the Decision to Add Solar to our Urban Roof

Here's the story synopsis so far; we own a VW Golf TDI that pollutes much more than VW claimed. VW has offered to buy the car back, and to replace it, we decided to buy an electric/hybrid Chevrolet Volt. Now we are figuring out how to power it without adding ANY carbon to the atmosphere.

The 2016 used Chevrolet Volt we purchased in September.
The 2016 Chevrolet Volt gets somewhere between 40 and 50 miles per charge, and then fires up a small gas engine to power the battery that actually moves the wheels. At my workplace, the company is offering free charging as part of a pilot electric vehicle program. I spoke with the person in charge of the electric vehicle (EV) program and while they don't have any plans to end the pilot, as more people by EVs, they may start charging a fee to juice up or it will get increasingly difficult to find an open charger due to demand. At a commercial-grade charger, tt takes about four hours to fully charge 50-mile battery. With two stations, that means about four cars can juice up in a typical 8-hour work day.

So for now I could charge the vehicle at work. BUT, the power I get there is still from a coal or natural gas-fired power plant emitting carbon dioxide into the atmosphere.

We could go start to purchase energy from the Madison Gas & Electric (MG&E) green power program. This allows us to pay a premium for sustainably-generated electrons. Now, I know that the electrons made on a wind farm in Iowa, or from a solar array far from Madison aren't actually going to come to my house, but the point is that we're paying a premium so that sustainable electrons are being made somewhere. However, what's the actual return on investment (ROI) of the premium paid for those electrons? There is less carbon in the atmosphere. And we're encouraging our local power utility to do more such sustainable projects. But I'm thinking about an actual dollars and cents ROI on an investment into clean energy.

As I pondered a replacement for the Volkswagen, I took a tour this summer that opened my eyes to Claire Strader had an open house and I had always wanted to see her garden and yard. She's a farmer, so I wanted to see how she took her big-scale farming knowledge and applied it to an urban lot. I saw her lovely front yard vegetable gardens, her orchard in the back and a few busy bee hives. And then she told us to turn around and pointed out the the new solar photo voltaic (PV) array that had been installed on the roof just weeks before. Roughly a third of her total roofdirect current (DC) electricity. An inverter converts it to alternating current (AC) which is fed into the local utility's power grid. An electric meter on her house tracks energy created and used.
was covered in panels. These panels capture sun and generate
new possibilities. A friend of mine,

"This is all fine," you say, "until a cloudy day or at night, or even in winter when the days are short." You are right, all of these things are still true even when you put a PV array on your house. So, what does Claire do when she wants lights in the winter or at night?


During the day, she generates and adds electrons to the utility's network and other people use it. When adding electricity to the grid, her meter runs BACKWARD. At night, and on cloudy days, Claire uses electricity from the utility network and her meter runs forward, counting up kilowatts used. And the next sunny day, it runs backward again. Do you see where this is going?Each month the local utility sends Claire a summary of the electrical energy she created and the energy she used and they reconcile. Maybe Claire used a few more kilowatts than she made, so she sends some money to the utility. And if Claire made more than she needed, the utility pays for the excess energy.

Well then, cover the entire roof with panels you say! In fact, Claire had lots of room to add more panels. Not so fast. Our local utility, MG&E sells energy to Claire for $.13 a kilowatt, but buys it back for $.04. Since it costs more than $.04/kilowatt to install panels, but less than $.13, it makes sense from a return on investment point of view to put on just enough panels to cover all your power needs, but not to overbuild the system. MG&E will pay you for it, but for pennies on what you pay to install the panels.

In the next segment of this mini-series, I'll write about what we decided to do to power our Chevy Volt without adding greenhouse gases to the atmosphere.

If you'd like to read all the parts of this series, you can see them here.
Part 1 - How Volkswagen is Helping us Repay the Planet for Its Sins
Part 2 - Our Search for a Cleaner Car
Part 3 - Buying a Used 2016 Chevrolet Volt
Part 4 - A Lesson on Creating Clean Energy at Home
Part 5 - Making the Decision to Add Solar to our Urban Roof