Once overshadowed by high costs and low aesthetics, residential solar energy applications are now brightening the landscape, thanks to technological advances and financial incentives. From IKEA to Tesla, it seems like everyone is getting into the solar game. But is it better to invest in a solar roof, add panels to your existing roof, or replace your roof in tandem with a solar installation? Do you want to make the solar system a seamless addition to your home or bring it front and center to showcase your commitment to a sustainable future? Successfully integrating solar into a house calls for considerable knowledge and design skills. Consulting with an architect will make your decisions much easier.
There are different forms of collecting solar energy for your home. Solar energy can be converted to electricity through photovoltaic (PV) panels; it can heat your water with solar thermal panels; and your house itself could be the collector of passive solar energy, which is the absorption of radiant solar energy by building materials for later release into the house. For existing houses, PV systems are the most popular option.
A long-term investment with a shorter payback
Using solar panels for your electric power needs can save money, depending on where you live, the amount of energy the panels can collect, the season, climate, and location. The positive contributions of solar energy, which creates jobs and supports energy independence, has influenced governments, utilities, and other groups to implement tax credits and rebate programs to help make solar energy more available to homeowners. The combination of solar tax credits and cash rebate programs can lower the cost of a solar installation by 30 to 50 percent.
In addition, Stephanie Horowitz, AIA, the managing director of ZeroEnergy Design, points out that solar offers yet another way to reap rewards. Solar Renewable Energy Certificates (SRECs) can be sold to utilities by homeowners. According to EnergySage, 30 states and the District of Columbia require electric utilities to produce a set portion of their energy from renewable sources or pay someone who does through an established trading market. Every 1000 kilowatt hours produced by a residential solar system earns one SREC. In some locations, an SREC is worth upwards of $300, according to some estimates. “If a PV installation has a five-year payback, and the homeowner has a 10-year SREC contract, that means they start getting paid to produce power from PV arrays after year five,” Horowitz says.
Horowitz explains the financial incentives of solar energy, and PV panels in particular, when helping clients decide on the use of solar. One factor in that decision is the amount of energy that will be produced. “It all depends on the local climate, the way the panels are installed, the direction they are pointed, and the efficiency of the panels themselves,” she says.
Planning for solar
When energy conservation is the ultimate goal, there are a few ways an architect can help a homeowner get started. “I talk about lowering the home’s energy consumption before addressing solar panels. Keep in mind the passive strategies first,” Horowitz. says Air infiltration can account for one-third of a home’s heat loss, so countering it is critical. The architect will generally start with adding insulation, improving air sealing, and evaluating upgrades to the mechanical system.
Likewise, David Vandervort, AIA, of David Vandervort Architects, says, “We always start with passive strategies and maximize them in the design. Then, if the budget allows, we will add PV panels to the extent feasible and work with the local solar company to assist our clients with questions and estimated costs.”
When an architect helps plan a solar installation, aesthetics will be addressed. Some clients and architects will want to hide the PV panels from public view behind parapet walls. Others will want to make them visible. “Part of this is philosophical,” Vandervort says. “A well-designed solar roof installation does not have to look unsightly, but instead can show a client’s interest in thoughtful environmental priorities.”
When deciding among the increasing number of solar PV applications—including fixed panels, PV roofing shingles, or even paint-on nano-size PV cells—some architects are cautious. The decision rests on a number of factors. Real slate roofs don’t readily lend themselves to solar panels. Nor does a roof built to older codes or with structural problems. “If we are renovating a house and have free access to rafters, we might reinforce the roof to accept solar panels,” Horowitz says. But she believes it is not economically feasible to completely rebuild a roof just to add solar.
As for the emerging solar roofing tile systems, Horowitz thinks that building integrated PV products on the horizon are important to consider, but so are the systems they are replacing. It is critical for a roof to be weathertight, and the solar roof tiles have not yet been proven to be so. However, she has confidence in PV panels on top of metal roofs attached with clip-on brackets, and also on top of asphalt roofs when correctly installed. She believes there is greater efficiency, with better economics, using conventional PV panel systems on conventional roofs.
The coming revolution
Next on the horizon will be advances in battery storage of electricity. PV panels produce electric energy that must be used immediately or else stored. Battery development is advancing rapidly, but has not yet reached its optimum in cost-benefit trade-offs. Horowitz is now planning for future battery systems in many of the houses her firm designs. She adds the wiring and tries to find a dedicated battery space with 3’ x 6’ of floor space to stack batteries. She sees the costs of batteries trending down, alongside the cost of PV panels, and anticipates widespread use within three years.
About the author: Elena Marcheso-Moreno writes about architecture and design from McLean, Virginia.