Solar Panels and EV charging for ARRL?
The gift that keeps on giving...

See also EV Charging at ARRL HQ

Solar Donation Initiative? For the ARRL with a long term mission and commitment, the demand of the never ending monthly utilities is a perpetual drain on finances. Solar power, on the other hand can not only eliminate this nuisance but significantly reduce the overall long term operating cost. Solar became competitive with the utilities by 2011 and can now provide power in perpetuity at much less than half the cost of the utilities. Long term stewardship of member's funds almost demands this path to the reduction of such never ending costs. The graphic at right shows the exponential growth of solar in 2010 as many of us began investing in solar. But then we had to scale down the chart by 25-to-1 just to fit the 2015 global production to fit! And now it is 2020!

Return on investment: Although a non-profit ARRL solar project cannot take advantage of the 21% federal income tax credit, this is offset by the unique ability for members to make individual tax deductible contributions towards the individual purchase of solar panels in their name. This one-to-one association of hardware component to donor identity has a powerful motivational benefit. Further the rate of return for any solar investment is near ten percent or more annually, forever. And the actual effective rate only goes up over time as utility costs rise. If the ARRL holds any funds in other long term unrestricted investments that are not generating this rate of return, then they could also be considered as additional sources of initial investment for long term savings.

System size: To guess at the size the system we use the NREL online PVWATTS calculator which includes a 30 year climate model and is the gold standard for very accurate real world power predictions. For an assumed ARRL $2000 monthly electric consumption including weather effects, at 14 cents/kWh, an array size of 120 kW is required. (turns out the ARRL spends almost $8k per month for electricity) A sketch of such an array is shown above. Although the current contractor priced solar system cost is around $2.50 per watt, the actual cost of the solar panels themselves and share of the inverter costs is about $1/Watt and can be added incrementally very easily.

Buy-a-Panel Funding Model: The funding model for the ARRL would be mostly through individual donations, with the array grown over time. There is a significant advantage to this approach. To get started, a modest initial installation via contractor is essential. This will provide the necessary building and electrical permits, the utility inspections and establishment of a commercial net metering account. But once this formal process is complete, then the organization's own electrician can add solar panels incrementally as needed at much lower cost as donations and time permit.

Solar Orientation: The ARRL property has an excellent solar orientation with good southern exposure as shown in the figure above. This allows plenty of room for the dual high 70 panels on the roof leaning against the penthouse and a row of 50 panels along the roof line. Four other rows of 50 panels can be installed along the side road and another 40 panels in the front parking lot. A final dual row of 60 panels could go along the north edge of the back parking lot with some tree trimming. The five ground mounted rows of 50 panels each along Starr Road are kept at the single panel height comparable to the 6' zoning height limitation for fences. Similarly, maybe a 15 foot setback with a variance to local zoning could be obtained. Hartford County is a national leader in solar development and encourages local planning and zoning to favor solar and make accommodations where possible. See their Connecticut PV Permitting Guide

Grid-Tie, Net Metering: It must be understood that there are no batteries for solar energy storage in modern economical solar systems. That is a very common and costly mistake of Ham operators who think in terms of batteries for energy storage. Modern solar systems are designed for economical power via grid-tie net metering 99.9% of the time and have nothing to do with backup power which is only needed 0.1% of the time. Backup and emergency power with a grid-tie system are no different than what is used now for backup. That is, a conventional generator and supply of gas is far more economical than a huge investment in batterys that are only needed 4 hours a year. For critical circuits needing overnight battery backup for long term outages, each such circuit can be easily matched with an overnight battery to match the requirement.

In addition, modern high voltage string inverters such as the SMA shown at right are available with an additional standard 15 amp 120 VAC output circuit for backup power while the sun still shines. For the ARRL sized array with 20 such inverters, that would be 20 such 15 amp circuits. Even under a cloudy overcast sky, a 120 kW array would still be able to supply all of these backup 120vac circuits at half load. For operations at night, only minimal battery backup on individual circuits could be added. Trying to store full solar output is simply not cost-effective. (Though in the future, a small battery system such as the TESLA power wall could provide peak power to avoid demand charges,)

Suggested ARRL approach: The goal of this project is not a new huge cost impact on current finances. The goal is to have an overall top-down approach to long term minimization of utility costs by possible adjustments in current holdings, and a significant fund-raising campaign to members. Here are some thoughts.