Solar

The Dawning of Solar Electric Architecture

The last two decades have brought significant changes to the design profession. In the wake of traumatic escalations in energy prices, shortages, blackouts, embargoes, and war, along with heightened concerns over pollution, resource depletion, environmental degradation and climate change, awareness of the environmental impact of our work as building design professionals has dramatically increased.

In the process, the shortcomings of yesterday’s buildings have also become increasingly clear: Inefficient electrical and climate conditioning systems squander great amounts of energy; combustion of fossil fuels on-site and at power plants adds greenhouse gasses, acid rain, and other pollutants to the environment; inside, many building materials, furnishings and finishes give off toxic by-products contributing to indoor air pollution; and, poorly designed lighting and ventilation systems can induce headaches and fatigue. Solar Energy CubeArchitects with vision have come to understand that it is no longer the goal of good design to simply create a building that’s aesthetically pleasing-buildings of the future must be environmentally responsive as well. These architects have responded by specifying increased levels of thermal insulation, healthier interiors, higher-efficiency lighting, better glazings and HVAC equipment, air-to-air heat exchangers, and heat-recovery ventilation systems. Significant advances have been made, and this progress is a very important first step in the right direction. However, it is not enough. For the developed countries to continue to enjoy the comforts of the twentyfirst century, and for the developing world to ever hope to attain them, sustainability must become the cornerstone of our design philosophy. Rather then merely using less of the non-renewable fuels and creating less pollution, we must come to design sustainable buildings that rely on renewable resources to produce some and, eventually, all of their own energy and create no pollution. It may come as a surprise to many architects and their clients, but every building they are currently designing to rely on fossil fuel will become obsolete within its lifetime as the world’s remaining reserves of oil are drawn down and prices rise to the point that simply burning oil for its thermal content can no longer be justified. Oil industry analysts (who should know the subject) expect world oil extraction to peak within the next 5 – 10 years. After that, we will begin the long and irreversible downward slide where demand will greatly exceed supply and prices escalate. The heads of Shell and BP Oil have both stated publicly that the end of the oil era is in sight while also calling for immediate action on global warming and climate change. As the era of cheap oil draws to a close, we must begin in earnest to develop other energy options to power our buildings as well as transportation, agriculture and industry. Olympic Aquatic Center - AtlantaOne of the most promising renewable energy technologies is photovoltaics. Photovoltaics (PV) is a truly elegant means of producing electricity on site, directly from the sun, without concern for energy supply or environmental harm. These solid-state devices simply make electricity out of sunlight, silently with no maintenance, no pollution and no depletion of materials. Photovoltaics are also exceedingly versatile – the same technology that can pump water, grind grain and provide communications and village electrification in the developing world can produce electricity for the buildings and distribution grids of the industrialized countries. There is a growing consensus that distributed PV systems that provide electricity at the point of use will e the first to reach widespread commercialization. Chief among these distributed applications are PV power systems for individual buildings. Interest in the building integration of PV (known as BIPV), where the PV elements actually become an integral part of the building, often serving as the exterior weathering skin, is growing world-wide. Photovoltaic specialists from more than 15 countries are working within the International Energy Agency on a 5-year effort to optimize these systems, and innovative designers in Europe, Japan and the US are now exploring creative ways of incorporating solar electricity into their work. A whole new vernacular of Solar Electric Architecture is beginning to emerge. The Opportunity Energy planners have long envisioned large central-station, utility-scale, solar power plants covering huge expanses of desert. While this vision has many favorable attributes, the economics bear careful investigation. Ground-mounted PV plants require the allocation of land which must be acquired and made ready to accept the PV system. The cost of land and the cost of site work to prepare the land can be considerable. In Europe and Japan, the lack of available large open tracts of land has effectively precluded the central-station PV option. Once the land is cleared and made ready, foundations and support structures must be constructed to support the large PV arrays. Long wire runs must be installed to connect the PV arrays to the power conversion equipment. A building or buildings must be built to house the power conversion equipment. A connection to the power grid must be made which requires a substation, transformers and special switchgear. If the transmission and distribution grid is not right nearby, the cost of the line extension can be considerable. A fence must be constructed to secure the plant, a staff of trained operating personnel will be needed to manage it and it is likely that real estate taxes will be assessed on the facility. Once complete, the plant will generate solar electricity to be sold to the utility grid or to another party at the wholesale rate in competition with the utility’s avoided conventional fuel costs. The plant must compete for financing based on its investment merit. There are O&M and sales costs and the revenue received is always going to be much lower than the utility’s retail rate for power. Contrast this with the benefits of distributed PV systems which:
  • Provide grid support
  • Eliminate costs and losses in transmission and distribution
  • Create a diverse and resilient energy system
  • Typically require no special approvals or permits
  • Can be fielded very rapidly
The most attractive distributed applications are PV power systems for individual buildings:
  • Buildings and the processes they house consume the majority of electricity
  • The real estate comes ‘free’ with the building
  • There is no real estate tax on land to support the PV system or on the PV itself
  • There are no site development costs – as they are part of the building construction
  • The utility interconnection already exists to serve the building
  • Displaces kWh on the customers’ side of the meter at the retail rate
  • Provides utility demand charge reductions
  • Delivers additional financial benefits under time-of-use rates
The building integration of photovoltaics, where the PV modules actually become an integral part of the building, often serving as the exterior weathering skin, is growing world-wide.
  • The building itself becomes the PV support structure
  • System electrical interface is very easy – just connect to a distribution panel
  • Building-integrated PV components displace conven-tional building materials and labor, reducing the net installed cost of the PV system
  • The architec-turally clean, well-integrated systems increase market acceptance
  • Building-integrated PV system provide the building owners with a highly visible public expression of their environmental commitment.
With building-integrated PV systems, building owners are already paying for facade and/or roofing materials and the labor to install them. The land is already paid for, the support structure is already in place, the building is already wired, the utility is already connected and, developers can finance the PV as part of their overall project. Another benefit comes from distributing the BIPV installations over a very broad geographic area and a large number of buildings, mitigating the effects of local weather conditions on the aggregate and, producing a very resilient source of supply. With reduced installation costs, improved aesthetics and all the benefits of distributed generation, building-integrated PV systems are the prime candidate for early widespread market adoption. Innovative architects the world over are now beginning to integrate PV into their designs and, PV manufacturers are responding with modules developed specifically for BIPV applications, including integral roof modules, roofing tiles and shingles, modules for vertical curtain wall facades, sloped glazing systems, and skylights. Author Access: Steven J. Strong is President of Solar Design Associates, Inc., a group of Architects and Engineers dedicated to the design of environmentally responsive buildings, and the engineering and integration of renewable energy systems which incorporate the latest in innovative technology. Steven J. Strong, President Solar Design Associates, Inc. Harvard, MA 01451-0242 (978) 456-6855 (v), (978) 456-3030 (f) [email protected]