Solar Builder

JUL-AUG 2018

Solar Builder focuses on the installation/construction of solar PV systems. We cover the latest PV technology (modules, mounting, inverters, storage, BOS) and equip installers/contractors with tips and tools to make informed purchasing decisions.

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14 J U LY / AU G U S T 2 0 1 8 levels of deployment were Illinois, Ohio, Florida, Pennsylvania and Texas. At a high level, patterns of LMI poten- tial mirror overall income trends. LMI solar potential percentages are greatest in the lower income communities and higher in rural counties. Spatial trends in the potential for solar to offset LMI consump- tion most strongly reflected regional varia- tion in per-capita electricity consumed, primarily due to which fuels are used for building heating and cooling loads. Impact on the future The Solar Energy Technology Office of the U.S. Department of Energy updated the cost targets of 5 cents per KWh for residential solar by 2030. Using these costs and making forecasts, NREL estimated that achieving them would result in 970 GW of PV capacity 2050, or 33 percent of the generation mix. But can we hit that target leaving the LMI solar rooftop seg- ment in the dust? Using this data set, NREL examined the feasibility of rooftop offsetting that much in each county in the United States given the technical potential. Offsetting 33 percent of LMI house- hold electrical consumption ("offset tar- get") with rooftop solar is technically fea- sible on a national scale when only consid- ering households in SFOO buildings, although to do so requires buildout on essentially all SFOO buildings — an impractical and unforgiving market chal- lenge. In contrast, on a technical basis, there is more than sufficient roof space to meet the 33 percent offset target when including single-family rental-occupied (SFRO), multifamily owner-occupied (MFOO), and multifamily renter-occu- pied (MFRO) buildings. Using only the popular SFOO seg- ment, 60 percent of counties would have potential to meet 33 percent of LMI electricity consumption. Said in reverse to belabor the point: 40 percent of U.S. counties have insufficient rooftop poten- tial to offset 33 percent of LMI electric consumption in just single-family, own- er-occupied. The current path to 2050 will not achieve the target generational mix. But including rental and multifamily there is "more than sufficient rooftop space to meet the 33 percent target." NREL believes 99 percent of counties would meet the 33 percent threshold in just residential rooftop capacity. Reaching this potential requires deploy- ment models other than those commonly found today. Such models would need to ensure the rental owner had incentive to install solar on their own buildings, like bundling utility expenses with rent pay- ment as a means of passing the costs and savings along to tenants. These models would also need to address diverging requirements and energy burdens of own- ers and tenants in multifamily. It takes a village The NREL study shows that most LMI electricity consumption (especially with the LMI segment requiring a lower thresh- old to offset onsite) can be met with roof- top solar, but again 100 percent deploy- ment is unlikely. To get to these high levels of penetration would require deployment on non-traditional building types. NREL posits one way to increase LMI access to solar is through the vast network of nonprofits that connect to this segment. What if PV systems on government build- ings, public housing, schools, shelters and places of worship were intentionally over- sized to benefit their LMI communities with the excess generation? The NREL team estimated this opportunity for three cities — Chicago, San Bernardino- Riverside and Washington, D.C. — based on building size, average electric consump- tion and solar technical potential for out- sizing each of those buildings segments. They found enough gross generation potential on those selected building types to meet between 10 to 30 percent of LMI consumption, but only about 1.5 to 9 per- cent after accounting for the onsite con- sumption. Schools have the greatest opportunity to export to the community because of their typically large flat roofs and lower levels of electrical consumption in the summer when irradiance is highest. Places of wor- ship came next because of low levels of consumption year round and moderately favorable roofs. Public housing sites and homeless shelters likely have insufficient rooftop areas to offset 100 percent on site consumption. National nonprofits GRID Alternatives and Vote Solar updated their Low-Income Solar Policy Guide which explains some proven strategies for expanding solar access being used in states and cities across the country. In multifamily, for example, suc- cessful strategies include: Net metering or other incentives to ensure full value of solar Financial incentives to reduce upfront costs, overcome split incentives sce- narios and ensure benefits reach ten- ants Measures to reduce barriers to financ- ing Technical assistance to affordable housing providers, participating con- tractors and service providers Pairing solar with energy efficiency programs Facilitating waivers from regulatory utility and rent allowance requirements to maximize tenant benefit. (Under a utility allowance formula, a resident's rent plus utilities equate to a certain percentage of the resident's income. When a resident's utility bills decrease, as can happen with solar, the rent por- tion will automatically increase under the formula) Integrating job training and employ- ment opportunities in the solar energy and energy efficiency sectors of the economy California and Washington D.C. are the only examples of active programs in place specifically targeted to deploying solar for multifamily affordable housing. California has an incentive program dedicated to affordable housing multifamily, with requirement that half of energy generated on site be used to serve tenants loads. IN THE NEWS Check this out We have an article on an innovative solution that could solve a lot of these issues. Check it out on page 27.

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