Q & A
CHP, Combined Heating and Power, generates electricity and heat, typically within your premises. CCHP adds cooling, and balances the load for all seasons. The combination has better fuel efficiency than thermal generating plants, and when run on site, can achieve 80%+ efficiency. Although the plants are small compared to the Hydro grid, they can cut costs to (often) 1/4 of the normal electricity cost, because the Hydro bill has so many extraordinary charges. This often pays for the very expensive machines in as short as 3 – 5 years, with no government assistance.
The BROAD chiller is an absorption chiller providing cooling through the change of phase of water vapor, under vacuum, in the presence of Lithium Bromide salt solution. The process is regenerated using the CHP’s waste heat. Since only water and lithium bromide solutions are pumped, electrical demands are negligible, displacing air conditioning compressors that would otherwise use a lot of electricity. Within the machine’s footprint, it can also include a boiler driven either from the waste heat or a supplementary gas flame, at efficiencies up to 93.5%. Should the CCHP waste heat be insufficient, heat can come from biogas, propane, or waste steam, or by condensing the exhaust of a mid-range boiler.
BROAD is a major manufacturer of absorption chillers and chiller/boilers with over 35,000 installations world-wide. They are based in China. G7HVAC Inc. is the Canadian representative.
That depends on economics, the trade-off between equipment cost vs. savings. Ontario facilities over 1 Megawatt of power usage, facilities that require standby power, and facilities that need very high quality, consistent power, can usually justify running entirely from CCHP with supplemental power conditioning.
You do not have to “break the umbilical cord”. The grid can remain there as your backup, but that can result in “minimum connection” charges. Those charges may justify an over-capacity of CHP, spread out over several machines, so that the system can be maintained in part while the facility keeps running (true “always-on” operation).
For facilities that cannot justify full “islanding” of their CCHP, the cogeneration option can yield partial benefits. Since this means the generator is in-effect on the grid, it requires full Hydro approval (a CIA).
There are many answers, but for major problems, you need a UPS. Just as you use a UPS for your home computer, huge UPS’s exist to protect your whole plant. They need to be chosen and installed carefully.
If you just use the UPS, it is a cost justified by the production problems it avoids. If you add CCHP, it saves most of your electricity bill. The UPS is good, but the UPS with CCHP is better.
Combined Cooling, Heat and Power. CCHP adds an absorption chiller (BROAD) to a CHP motor-generator, to get cooling from waste heat in the summer. This tends to balance the system, so that all energy is usefully employed year round, and permits the use of a much larger CHP system.
Combined Heating and Power. A motor-generator set makes electricity, and the recovered jacket and exhaust heat provide space and water heating.
Connection Impact Assessment. Before Hydro allows active electrical equipment on your site, they do an assessment, looking at the impact that equipment might have on the local grid and beyond.
The “co” in cogeneration means that 2 things are being generated together. In the strictest meaning, this refers to making your own electricity on equipment that is exposed to Hydro’s grid. You generate on the same grid as Hydro’s power stations.
Strictly speaking, “hydro” is based on the Greek word “hydra” for water creatures. We refer to the Ontario electric utility as Hydro because it started off using water power as its prime source. While the bulk of the power is now nuclear, the term remains. In this web site’s context, the capitalized “Hydro” means the electric utility, whoever the local one might be.
Islanding is the term for running a CHP generator outside the Hydro grid, an “island” of its own power. Provisions have to be made to power the control electronics at all times, and enough power to do a “cold” start. Once running, the CHP can recharge that standby power.
Another word for CCHP. It refers to the three forms of energy: electricity, heat, and cooling, done in one combined process.
Uninterruptable Power Supply. These devices are similar to your home UPS protecting your computer, but on a huge scale.