Creating Your Personal Power Plant
Part 4
Connecting the Heart of the System
Follow along as President Greg Garrison goes solar in this mini-blog series.
In my last post, the construction of my solar installation had begun. In this post, I want to talk about the heart of my energy transition — the solar power plant.
I still marvel at the science behind solar energy — there would be no energy transition if there were no simple way to convert sunlight to the AC power I use in my home. My power plant will convert light energy from a star 92,000,000 miles away into electrical energy that I can use, store, or export to my neighbors on the electrical grid. In a single hour, the sun generates enough energy to power the lives of every human on earth for an entire year. And yet, even in 2022, solar energy seems unique because we are conditioned to believe that energy should be combustible, transportable, and ubiquitous — an ideology our society has accepted to our detriment. Solar, wind, and hydro, along with energy storage, however, are disrupting that paradigm.
My power plant will have 23 REC 405-watt panels (9,315 watts DC) mounted on the roof of my house and attached garage. I would have installed more, but 23 panels will fill the available roof space. Solar panels are big. The panels installed on my roof are six feet tall and over 3 feet wide — bigger than the installers installing them! For scale, my garage roof plane is 24’ X 14’ (336 sq ft). That area will accommodate ten 405-watt panels or 4,050 watts (12 watts per square foot).
If my system were situated in full sun, I could produce 11,000 plus kilo-watt hours (kWh) a year, but since my site is shaded, I will produce around 8,000 watts a year. In the last year, the house consumed 4,800 kWhs of electricity. So even with adding mini-splits and an electric vehicle, I should achieve 95% energy independence from the grid. Energy independence only occurs when you balance your energy production with your energy consumption.
Making Progress
At this point in the installation, the racking crew, Cris, Bob, and Roy, have attached the mounting feet, leveled and squared the horizontal rails, and bolted on the Enphase microinverters. This is the stage where the project gets turned over to the assigned electrician and his apprentice — in this case, Jeff and Farlin.
Jeff and Farlin had a lot of work ahead of them just to bring the power from the roof — wire twenty three individual inverters into two separate electrical strings, combine the inverter strings in roof-mounted combiner boxes, and fabricate electrical conduit piping from the roof to each of the devices the power from the solar array will flow through. Bending, combining, and fastening all the conduit would take the better part of a day. I was sitting upstairs working when they started pulling wire from the roof through the conduit. It sounded like squirrels running across the roof and down the wall.
Ok, bear with me; I am about to get technical and nerdy for a minute. I am using an Enphase integrated system, which connects not only the different components of my system to each other but also me as the homeowner. The Enphase microinverter converts DC power to AC power, then controls that power, stores it, measures production and consumption, and reports back on grid and battery activity. This is the cool part: through the Enphase app on my phone, iPad, or computer, I can access and assess the health of my system — and monitor my energy interdependence. I’ll be going into the details in a later blog post, but for now, the Enphase energy system, considered the best in the industry, has been a great source of information and
wonder.
Enphase offers four energy configurations
- Solar only
- Sunlight Backup
- Home Essentials Backup
- Full Energy Independence
I am installing the Home Essentials backup; 85% of our clients chose this option. It is the best entry point for a homeowner who wants energy security and full energy management. Call our team to find out which configuration is best for you.
What often surprises most clients is the number of components that need to be installed and where they need to be installed. I, too, was astonished to realize that in addition to the solar panels and inverters that are installed on the roof, my system would also include:
- Enphase IQ Load Center
- Enphase IQ system controller
- Enphase IQ Battery
- Backup Loads Panel
- Utility disconnect
- Battery disconnect
- System disconnect
- Rapid Shutdown Switch
All of these components take up serious real estate. Generally, all the Enphase components and the backup loads panels can be installed in the home, typically in the basement. The wall space needed to accommodate these components is roughly the same as the space needed to store that unused elliptical machine, tubs full of Christmas decorations, and ten large boxes marked “Tag Sale Stuff” — about half the basement wall. The disconnects and rapid shutdown switch need to be installed on the exterior wall within sight of the utility meter. All the components except the backup loads panel will be installed on the exterior of my house. (more on this in a later post)
Jeff and Farlin will need to wire all of these devices so they are interactive with each other, my home, and the electrical grid. If the grid goes down, they have to ensure that the battery, controller, and backup load center continue to power the essential circuits in my home.
Mounting, wiring, and connecting all the components took three days. Yes — Jeff had to put another hole in my foundation. Unlike the sewer, water, cable, utility, dryer, and furnace holes in the foundation, this hole was just large enough to snake the electrical wires for the system from the outside to the backup loads panel. Thanks to Jeff’s attention to detail (he would say OCD), all of the components, connections, and devices were installed straight, plumb, and secure. He even installed the disconnects in line by size; when he was done, they resembled Matryoshka dolls.
The Finishing Touches
On Day Five, members of the racking crew returned to install the solar panels on the roof. This was the big day and the final step of installation. Up to now, the system is a collection of inert and powerless pieces and parts. Once the panels are installed, power will flow to all the installed components throughout my home. It may seem like hyperbole but when those panels went up, I felt both the power of the moment and the power that was being transferred to me. It was awesome.
Until I had Northeast Solar install my home power plant, my relationship with the energy in my house was limited to the usual bare minimum: installing energy-efficient lighting and turning down thermostats — and looking at my electric bill with some dismay. With a solar power plant on my roof, the power was now mine to use and control. This amount of control is possible because I elected to add storage to my system. Without storage capability, my system's energy is just a collection of excited electrons looking for an electrical load to power. What could not be used in my house would flow onto the grid to my neighbors’ homes. The addition of a battery allows me to control those electrons and store them for my home’s use. On an average sunny fall day, my system will fully power my home for 24 hours and still have a little energy left to export into the grid. It’s an absolutely seamless transition. But not everyone needs to or can start off with a battery — just having solar and no storage is still an excellent choice, and everyone who can should do it.
When the panels were installed and connected, Jeff started throwing switches. Blinking lights were the only indication that we had power. Jeff facetiously told me that it was a good sign. He went through each device and, using an app, walked through the commissioning process. A call to Enphase tech support allowed him to push through software updates. After everything was commissioned and operating, Jeff shut everything down. There was still one last step.
The Last Step
All solar energy systems have to be approved by the local utility and require a bidirectional utility meter. The meter installation and approval can take anywhere from one to three weeks. My approval took ten days. On the day the utility issued my ATO (Approval to Operate), I happened to be at home. I turned on the system myself (we do allow most clients to do their own startup, but we also will come out and do it for the client). Once the system powered up, I opened my Enphase Enlighten app on my phone, and for the first time saw power flowing from the solar panels on the roof into my home. I went inside and turned on a light — a simple and thoughtless act previously, but now it seemed almost magical. Sunlight from our local star was powering that light! The solar energy flow might become less fascinating in time, but it hasn’t yet. I love opening the app at night and watching the flow of energy from battery to my home. It is so cool! And — I am more aware of my energy usage than I have ever been. We all should be.
In my next post, I will discuss why I installed a battery and how it has changed the way I look at energy.