Thermal Energy Upgrade

Thermal Energy Upgrade Program with Fortis

The Thermal Energy Upgrade Program is a unique partnership between the Delta School District and Fortis Alternative Energy Services (FAES) whereby FAES will undertake the work to replace and convert the heating/cooling plants of the remaining 19 sites in the District inventory not yet upgraded, assume ownership of these plants plus two previously upgraded plants, operate and maintain the 21 plants, and then charge a tariff to the District for “thermal energy” consumed much in the same fashion FAES charges consumers for natural gas consumption and BC Hydro charges for electricity consumption.  The project also includes the work necessary to alter and connect existing mechanical systems at those buildings to accept the new technology.

This approach to purchasing thermal energy pools the costs and benefits of each building in a manner that enables the District to maximize the environmental benefits of employing alternative technologies in a timely manner (two-year implementation period) while managing capital and operating costs within existing, tight constraints.

Technologies Used

  1. Closed Loop Geo-Exchange System (CLS)
    A closed loop system uses a continuous loop of buried polyethylene pipe.  The pipe is connected to the indoor ground source heat pump to form a sealed, underground loop through which an environmentally friendly antifreeze-and-water solution is circulated.  A closed loop system constantly re-circulates its heat-transferring solution in pressurized pipe, unlike an open loop system that consumes water from a well.  Most closed loops are trenched horizontally in areas adjacent to the building and where adequate land is not available, loops are vertically bored.  11 of the 19 sites included in this program will receive this form of retrofit.
  2. Condensing Boiler Upgrade (CBU)
    In a conventional boiler, fuel is burned and the hot gases produced are passed through a heat exchanger where much of their heat is transferred to water, thus raising the water’s temperature.  One of the hot gases produced in the combustion process is steam, which is for all intents and purposes wasted.  A condensing boiler extracts additional heat from the waste gases by condensing the steam into liquid water, thus recovering its latent heat.  A typical increase of efficiency can be as much as 10-12%.  This is the least expensive of all of the alternative thermal energy systems considered in this project, and also yields the least amount of energy and carbon emission reduction.  Eight of the 21 sites included in this project will receive this form of retrofit.
  3. Air-to-Water Heat Pump System (AWHP)
    Similar to the air source heat pump systems the District installed over the past six years, air-to-water systems absorb heat from outside air, the heat pump compressor then increases the temperature of that heat further and a heat exchanger then transfers the heat to the building’s hot water heating system to provide a much higher efficiency solution over a conventional boiler system.  In the summer, the system can work in reverse to assist with the cooling of the building, if the building had a cooling plant pre-existing.  Two of the 21 sites included in this program will receive this form of retrofit.

Pertinent Project Data

  1. Buildings Included:
    –  Delta Secondary (CLS)

    –  English Bluff Elementary (CLS)

    –  Pinewood Elementary (CLS)

    –  Richardson Elementary (CLS)

    –  South Delta Secondary (CLS)

    –  South Park Elementary (CLS)

    –  Delta Manor Education Centre (CLS)

    –  Neilson Grove Elementary (CLS)

    –  Delview Secondary (AWHP)

    –  North Delta Secondary (AWHP)

    –  School Board Office (CLS)

    –  Annieville Elementary (CBU)

    –  Beach Grove Elementary (CBU)

    –  Chalmers Elementary (CBU)

    –  Cliff Drive Elementary (CBU)

    –  Heath Elementary (CBU)

    –  Holly Elementary (CBU)

    –  Ladner Elementary (CBU)

    –  District Maintenance Facility (CBU)

    –  Devon Gardens Elementary (CBU)*

    –  Sunshine Hills Elementary (CBU)*

    * – added to original program

  2. Project budget:  $6.4 Million
  3. Funding sources:  Fortis Energy Inc. ($5 Million), Public Sector Energy Conservation Agreement ($1.4 Million)
  4. Project Duration:  2 years, starting in Summer 2012 (boiler upgrades) and Fall 2012 (geo-exchange systems)
  5. Estimated Reductions:
  • Annual energy consumption:  32,000 – 36,000 gigajoules
  • Annual greenhouse gas emissions:  2,000 – 2,200 tonnes of carbon dioxide (= taking 400 – 450 cars off of the road annually)
  • Annual cost of utilities, taxes and carbon offsets:  minimum $50,000 initially
  • Heating and cooling plant upgrades and replacements avoided by the District over the next 20 years:  over $10 Million (which can be reinvested in other parts of the building and grounds infrastructure)