Designing An Energy Efficient Off-Grid Prefab Building Package:
I am always excited to hear from the clients who are looking at being or need to be off-grid. There is so much to think about and plan for on their new build, and Pacific Homes can help them in some of these areas. Over the years, I have had the opportunity to be involved in a few off-grid projects and have assisted clients by supplying them with a Pacific Homes Prefabricated Building Package to meet the requirements of their off-grids builds.
There are many different aspects to consider when going off-grid. In one instance, the clients may be building a small cottage and will have a small overall requirement as to what they need to be self-sufficient and enjoy their time out at their cottage. On the other hand, a client may be building their main home and have a totally different energy requirement for their family to reside on the property.
One will need to sit down and really run through all the areas involved in going off-grid, as this pertains to much more than just power requirements. There is general information, and some very helpful tools, online that can help shape the power requirements for a remote off-grid build. A new Canadian site that has recently come on board is https://energyhub.org/. It has some very interesting articles, common questions, rebate information and more. I also recommend searching some of the off-grid forums/bloggers and YouTube videos online as you will find many families going down this path that may already have firsthand experience with this endeavour.
Things to Consider When Going Off-Grid:
Observe the property and building site:
The property/building site and orientation are very important as you want to try and bring in as much passive solar energy during the winter months as possible while also shading from the sun’s heat during the summer months.
Make sure the design of the build is energy efficient:
This would include things like a very well insulated building exterior envelope and utilizing a better grade of windows and doors to create a well-performing, energy efficient building that will not require as much energy to heat during the winter or cool during the summer.
Power Generation Options:
There are many different ways clients deal with this area. Some of the different ways are Solar PV Panels, Micro Hydro and Wind Turbines. All of which generally would use a battery bank to store extra power for use at a later time such as at night, or when PV (Photovoltaic) panels are not generating enough power. This battery bank can provide AC power via power inverters rather than running a generator during this time. One important issue to keep in mind is phantom loads which essentially draw power on your system from items that even though turned off, are still drawing small amounts of power. When you add up all these small amounts it can quickly become a sizeable draw on the system whereas in a normal grid-tied situation, one wouldn’t even think about these power draws.
Generators come in many forms, sizes and fuel requirements. You will need to have one even if it is just a backup source. There are many types, wattage ratings, and fuel sources to choose from to best fit your situation
Water supply is another area where much consideration is needed as this could be dealt with in several different ways. One system could be a certified potable water cistern to store water that is trucked in.
Another option is a standard water well that is drilled. If you have a drilled well, there are specialized well pumps designed to work from off-grid power types such as solar, wind, batteries or generator. One manufacturer to research would be GRUNDFOS with their SQFlex product line https://ca.grundfos.com/products/find-product/sqflex1.html#brochures
Heating and Water Systems:
Heating and domestic hot water systems need to be considered. One method I have investigated, and has been used on a few of the projects I have been involved in, is In-Floor Hydronic Heat. This system uses a propane fired hot water boiler with the subfloor product called Warmboard to radiate the heat. This product uses a lower water temperature making it more efficient than some of the other methods used. Domestic hot water can also be produced by a propane boiler like the ones used for the in-floor heat. Some of the units available can actually look after both jobs.
6 Ways Pacific Homes Can Help With Your Off-Grid Project:
1) Using our Pacific SmartWall® Technology will improve the exterior wall thermal envelope performance on the build https://pacific-homes.com/pacific-smartwall-technology/
2)Make the appropriate adjustments such as add more insulation in all of the other exterior envelope areas like the attic, box joist and foundation areas
3) Adjust the overall heel height on the roof trusses (which is the depth of the truss at the edge of the exterior wall), due to the added insulation.
4) Sizing Solar Panel Loading on the roof trusses where the solar panels may be installed. There are very specific guidelines that we have to follow when designing the trusses in this area and these guidelines also require very specific installation requirements. Please review the current Solar Ready Guideline https://www.nrcan.gc.ca/sites/www.nrcan.gc.ca/files/canmetenergy/files/pubs/SolarReadyGuidelines_en.pdf
5) Use a higher performance window package using casement/awning/T&T style of windows as well as possibly triple pane units depending on the requirements of the project.
6) Use an energy efficient exterior door package to ensure an energy efficient envelope.
We offer our experience to our clients in the many other aspects of an off-grid build even if it is not something supplied in our building package. We get to see a lot of different projects in many different situations that provide us with quite a library of information to help our clients reach their goals.
If you are thinking about going off-grid be sure to give us a call as we would be happy to have an initial discussion and try to help wherever possible.