BY: John E Avenson avenson1@hotmail.com Westminster CO. There are several options available when considering Solar PV (PhotoVoltaics) for your home: HISTORY: Starting January of 2006, Colorado began the huge state rebate program for PV which triggered low prices enabling many folks to invest in PV for the very first time. In 2021, these old systems have seen a few forms of degradation. The following happened to my house: 1) The squirrels chewed through my cables on the roof and this had to be repaired, 2) The Power Inverter failed just a few months after the warranty expired and it had to be replaced. 3) NREL came to inspect my panels as part of a study to determine the average annual degradation of Solar PV collection efficiency. Their study showed that the average yearly reduction was 0.7% of the original rating. My old Sayo panels depreciated by 0.6% per year. My old 2006 panels were only 170 watts per panel. Today I have a brand new system using 400 watt panels. SO! What do you do with the old PV system? It is still working but I had outgrown its capacity due to purchasing more modern luxuries plus I added an Electric Vehicle which requires more capacity of an additional 3 KW system to the house load. 1) CHEAPEST: Option 1: The cheapest way to get your first Solar PV system is: My PV installation company offered to remove and take away the old system and deliver it to folks who want to purchase an old used system. My old 4KW sold for $2400 and the company packed it up and delivered it to the new owner. Today, many folks are upgrading their old PV systems. Perhaps you can put in a request to several PV installation companies and reserve an old second hand system for your home. 2) MEDIUM: PV panels have greatly reduced in price since 2006. New panels have individual optimizers that allow the array to fully operate even when there is a shadow on one or a few panels caused by a roof gable or tree. A new 4K system may be only $10,000 compared to 2006 when I paid $34,000 but with a huge rebate of $21,000. Today’s panels are so cheap that you can afford to place them on the east, west, and north sides of a roof in addition to the optimum south side. 3) EXPENSIVE: This past February the snow storm put stress on the Xcel power grid and my neighborhood lost power EIGHT TIMES in two days. I ordered a BATTERY BACK-UP system in addition to my new panels. A battery backup is more complex, involving a lot of wiring at the breaker box to customize which breakers I want to prioritize and remain on when the neighborhood goes out. I choose the keep the circuit that runs the house Internet, the lights in each bathroom, the kitchen lights, refrigerator and garage lights. PS: Your Credit Union has low interest rates to finance Renewable energy upgrades. The photo above is a graph of one day events for charging with Sun and clouds: 14KW system.

RESILIENCE: able to withstand or recover quickly from difficult conditions. This is a wonderful definition for how we want our homes to behave in bad weather and therefore be sustainable with the ultimate power of Mother Nature. The FEBRUARY TEXAS EVENT has shown how vulnerable our homes are in unpredictable weather. Plugging holes is the first and easiest step to staying comfortable, preventing frozen water pipes and reducing energy consumption. Only after that, can we consider adding expensive big-box items like replacing an old furnace, windows, or adding PV panels. Finally, Battery Back-up is becoming cheaper, but as long as the electrical grid is reliable, it is the last on the list for big ticket items to add. STEP ONE: Self Motivation! Within my power I can start with my own free labor: 1) A dd Weather stripping to my front door, (no daylight should shine through the top or bottom corners), 2) C aulk the Electrical boxes to stop drafts: the rear holes for wires and the front perimeter to the sheetrock for all electrical boxes 3) A nnually walk around the house exterior looking for and fixing any obvious holes and leaks (siding, windows, chimney, foundation, pipe holes etc.) (Use Weather proof tapes and caulk) 4) Search the house for Spider webs! Spider webs trap food to eat, and they will be located at air drafts, an indication of a two-way highway for little insects, up to snakes and mice. (Cans of Expanding Spray foam work well for these holes. If the weather is cold, heat the can up in hot water first.) STEP TWO: Hire an Energy Audit of my home. Refer to the Xcel Energy website for a list of the best companies. https://hvacree.net/xcel-co/public_search.cfm Xcel constantly checks the quality of these companies. Stick with your energy auditor as he/she walks around the house and learn what is of interest to them. DON’T BE SHY! They love to educate. STEP THREE: Read your Energy Audit summary. This is a list of the lowest hanging fruit to fix. The costs of action items will range from free stuff to expensive. JOURNEY: You and I are now on our way to a more sustainable and resilient community against the coming trends of bad weather due to global warming. Refer to this cheap book for more: