Journal | May 2011
Electricity. We all need (a lot of) it. Where does it come from? According to this linked article 45% of the electricity generated in the US comes from burning coal; with natural gas and nuclear at about half that each. Other renewable energy sources such as wind and solar only account for less than 4% (as of 2009). Yet, each standard lot in San Diego (5,000 square feet) receives on average throughout the year up to 2,325kWh (kilowatt-hour) of sun energy per day normal to a flat surface (calculated with data from the National Renewable Energy Laboratory – NREL). Coupled with average efficiency of photovoltaic collectors today at just 8% across all types (newer technology is approaching a theoretical efficiency of 29%) results in potential electricity generation per standard lot of 186kWh, which equals 67,890kWh per year. The average electricity consumption per household of three residents per year in 2004 for the San Diego Gas & Electric service area was 6,000kWh per year (rounded from The California Statewide Residential Appliance Saturation Study of 2004). Based on this rough data and calculation each standard lot containing a single family residence in San Diego receives 11-times the energy needed in the form of sunlight per year to provide the electrical power needs of the household.
This is not suggesting covering each lot completely with photovoltaics or that this is a broad-based solution to satisfy all of our energy needs. However, 455 square feet of solar panels would be sufficient to provide all the electricity needed for many households (assuming lower-cost low-efficiency panels and on-site storage ability) without requiring new transmission lines or new centralized electricity generation facilities – and reduce our dependence on foreign supplies of raw fuel.
What is a solar garage?
A beach house built in the mid-1980s on a narrow and steep lot directly above the beach is in desperate need of a facelift. This project consists of reconsidering the exterior in a Cape Cod / “Hamptons” residential style while only minimally adding building area to bring the significantly asymmetrical front elevation into compliance with the more symmetrical style of choice.
O.A.W. has been asked to design a new “modern Spanish Revival” residence based around an exterior courtyard exposed to the South for solar access. The initial concepts for this project include utilizing the whole site for indoor/outdoor living and separating uses within the residence depending on their status on the “Public-Private” continuum.
Accessory Dwelling Units (ADU) – formerly-known as “Granny Flats” – are secondary dwelling units on “single-family” zoned lots. ADUs are an opportunity to provide much-needed smaller housing units in built-out neighborhoods with minimal physical changes to the public’s experience from the street (ADUs are typically built to the rear of properties) and with minimal cost while traditionally providing opportunities for families to “age in place” and take care of one another while offering much-desired independence. Unfortunately, the City of San Diego has all but outlawed ADUs on single dwelling unit zoned property (Municipal Code Section 141.0302(b) “Companion Unit”) even after State law recognized their importance in housing the ever-growing (and ever-aging) California population (Assembly Bill 1866 passed in 2003 amended a previous ADU law by requiring local communities to allow ADUs as a property right). Fortunately, the County of San Diego has adopted a Second Dwelling Unit (SDU) ordinance allowing ADUs in certain circumstances.
Though O.A.W. has been interested in ADUs as a viable solution to ever-evolving housing needs for years, we have not had the opportunity to work on one – until this year. This project is a traditional ADU with an extended family living on the same property with mom moving from the main house to the SDU and son and his family moving into the main house (where he grew up). Limited to 30% of the existing main house’s living area, this 608 square foot SDU is designed to provide for gracious, comfortable, and affordable living.