Drake Landing Solar Community

The Drake Landing Solar Community (DLSC) is a planned community in Okotoks, Alberta, Canada, equipped with a central solar heating system and other energy efficient technology. This heating system is the first of its kind in North America, although much larger systems have been built in northern Europe. The 52 homes in the community collect solar energy in the summer and store it in an underground seasonal thermal store for retrieval in the winter. The system was designed to model a way of addressing global warming and the of burning fossil fuels. The solar energy is captured by 800 solar panels located on the roofs of all fifty-two houses. It is billed as the first solar powered subdivision in North America, although its electricity and transportation needs are provided by conventional sources.

How it works

There are 52 homes in this subdivision that contain an array of 800 solar panels. These solar panels are arranged on the roofs of garages located behind the homes. During a typical summer day these solar panels can generate 1.5 mega-watts of thermal power. A glycol solution (an anti-freeze solution; a mixture of water and non-toxic glycol) is heated by the sun’s energy and travels through insulated piping underground through a trench system to the heat exchanger within the community’s Energy Centre. This is known as the Solar Collector Loop. The glycol solution then transfers its heat to water located in the short-term storage tanks. The District Heating Loop begins with water being heated in the heat exchanger to a temperature of 40-50° within the Energy Centre. This lower temperature is more energy efficient, as solar collecting is more compatible with lower temperatures. This increases the total amount of heat available to each home. In the warmer months the previously heated water is taken from the short-term storage tank to the Borehole Thermal Energy Storage (BTES). The Borehole Thermal Energy Storage unit is 144 holes located thirty-seven meters below the ground and stretches over an approximate area of thirty-five meters. The water returns to the short-term storage tanks in the Energy Centre to be heated again in order to complete the circuit. During colder months the water from the BTES passes back to the short-term storage tank and is then directed to each home. Similar to a hot water tank, the heated water goes through a heat exchanger that blows air across the warm fan coil. Heat travels from the water to the air and is directed through the house via ductwork. When the temperature reaches that said on the thermostat, an automatic valve shuts off the heat transfer unit.

Energy centre

The Energy Centre building is a 2,500 square foot building located in the corner of the community. It is home to the short-term storage tanks and most mechanical equipment such as pumps, heat exchangers, and controls. The Solar Collector Loop, the District Heating Loop, and the Borehole Thermal Energy Storage Loop pass through the Energy Centre. Two horizontal water tanks occupy the majority of the space within the Energy Centre. These tanks are 12 feet in diameter and 36 feet long. The remaining space within the Energy Centre houses pumps, valves, heat exchangers and other necessary equipment to operate and control the energy system. These tanks are known as Short-Term Thermal Storage (STTS).

Borehole thermal energy system

The Borehole Thermal Energy System is located underground to store large quantities of heat collected in the summer to be used in the winter. It consists of 144 boreholes, which stretch to a depth of thirty-seven meters. At the surface the pipes are joined together in groups of six to connect to the Energy Centre. The entire BTES is covered by a layer of insulation, on top of which a park is built. When the heated water is to be stored, it is pumped through the pipe series. The heat is then transferred to the surrounding soil as the water cools and returns to the Energy Centre. When the homes need heat, water flows to the center of the BTES field and picks up the heat from the surrounding soil. The heated water then goes to the short-term energy tank in the Energy Centre and is pumped through the District Heating Loop to the homes.

Sponsors and partners

This project was conceived by Natural Resources Canada’s CanmetENERGY in partnership with governmental organizations and Canadian industries. Of the $7 million needed for this project this was the breakdown of funds:

• $2 million from federal government agencies.
• $2.9 million from the Federation of Canadian Municipalities and Green Municipal Investment Fund.
• $625,000 from the Alberta Government.

Community members

Homeowners were willing to pay for these energy efficient homes because it ensured high quality construction. Until the solar heating system began working, ATCO Gas (an Alberta based natural gas distribution company) fixed heating costs as $60 per month for the homeowners at the Drake Landing Solar Community. With rising fuel costs, this was a powerful incentive for homeowners to support the DLSC project. Even if the project had failed, ATCO gas would have replaced the special hot-water furnaces with traditional natural gas ones. There was limited risk to the homeowners and therefore encouraged these people to support the project.

Local sustainability

The 52 homes in Drake Landing Solar Community are certified to Natural Resource Canada’s R-2000 program Standard and the Built Green™ Alberta Gold Standard. The homes of the Drake Landing Solar Community were required to meet these standards in order to be Alberta Gold Standard certified:

• Upgraded insulation and vapour barrier systems that eliminate drafts and allow for balanced space heating and cooling.
• Lumber certified and produced by sustainable harvested sources.
• Engineered joists and load bearing components that are stronger, more structurally stable and were produced using sustainable manufacturing practices.
• Structural Insulated Panel (SIP) panel system at joist header areas ensures consistent insulation and vapour barrier (traditionally hard to finish space).
• Recycled materials in the drywall.
• Upgraded window systems that contribute to insulation.
• Advanced basement air gap wrap to drain water away from foundation and prevent moisture build up.
• Upgraded roofing material with longer warranties.
• 90% of the homes’ heating and 60% of hot-water needs will be met by solar power.
• Each home will produce up to 5 tonnes fewer Green House Gas emissions and a reduction of 110.8 GJ of energy per year than a conventional Canadian home.
• Each home will be 30% more efficient than conventionally built houses.

Costs and financing

• Each house sold for an average of $380,000.
• Homeowners are receiving an average of $60 per month solar utility bill for heating.
• $7 million for the initial start up of the Drake Landing Solar Community project.
• If this project were repeated it would cost $4 million, as approximately $3 million was for one-time research and development.
• Optimal community size would be 200-300 homes to realize the economies of scale. The number of systems would remain the same but the number of boreholes would just need to increase.

Awards

• 2011 Energy Globe Award in the FIRE category and the overall Golden Energy Globe World Award (Energy Globe Foundation Annual Awards Event) (2011)
• CanSIA 2006 Solar Awards for Solar Thermal Project of the Year (2007)
• Sterling Homes awarded the 2006 Emerald Awards for Climate Change from the Alberta Emerald Foundation (2006)
• Federation of Canadian Municipalities Sustainable Communities Award for Energy/Renewable Energy (2006)
• Recognized by Alberta Home Builders Association (2005)
• Sterling Homes presented with Sales and Marketing Achievement Award for Best New Idea of 2005 (2005)

International effects

A group of researchers form South Korea visited Drake Landing Solar Community in April 2012 to study the geothermal heating technology and how it can be applied to communities in South Korea, particularly ahead of the 2018 Winter Olympics in Pyeongchang.The main focus of this research trip was to learn about the economics and reliability of the technology.

Current status

On October 5, 2012 the DLSC set a new world record by covering 97% of space heating needs with solar thermal energy. You can keep up to date with the Drake Landing Solar Community solar thermal system by downloading the mobile version of the System's Current Conditions Dashboard app for iOS, Android and Blackberry 10. This is a convenient way to stay informed about the current conditions including outdoor temperature, incident solar energy, solar energy collected, solar fraction and space heating load. Systems Current Conditions App

External links

• Drake Landing Solar Community Retrieved on September 30, 2009
• Drake Landing Solar Community: Workings Retrieved on September 30, 2009