House with roof panels

Going off grid

2 Comments

Inexpensive and Simple

When many of us hear the term ‘off-grid’ in terms of our homes, it’s easy to think it must be difficult or costly to get a off-grid, however it is actually very easy to implement and not terribly expensive. When viewed in line with typical utility bills, it simply makes sense.

A typical off-grid system might range from $20-$30k to purchase, which is a significant upfront investment for most of us, but seen over the duration of a mortgage, it would actually translate into a very manageable monthly payment, e.g. $170 / per month. This is actually more affordable than many typical monthly utility bills for homeowners.

All change…or at least, a significant shift

At this point in time, almost every off-grid project requires a generator, because the sun is not always shining and the wind is not always blowing, and the capacity for storing the energy generated by these sources in batteries simply hasn’t developed sufficiently.

The problem with conventional off-grid systems is that they require propane or gas, which are petroleum based fuels. As we all know, this represents a simply unsustainable energy supply. Which is why we turn to biofuel.

Why not use readily available bio-fuel?

We recommend using a generator that can burn vegetable oil or bio diesel.  These are the fuels of the future as they are non-petroleum based and renewable.

A European company, Gelec Energy, has a great selection of generators, including ones engineered for use with vegetable oil/biofuel.

With this technology, no one is reinventing the wheel; they are simply making use of existing diesel technology developed over 100 years ago. After all, deeply concerned about the pollution that accompanied the age in which he lived, Rudolph Diesel originally designed his engine so that it could run off peanut oil…

As a fuel, bio diesel is also reasonably affordable, costing as little as $.60 per litre, compared to much closer to a dollar per litre for gas at the pump.

What this looks like

In the summer period (mid-March to mid-October) an off-grid house is designed to run off solar PV panels and batteries. In the winter period (mid-October to mid-March) it’s engineered to run off a combination of solar PV, batteries, and the generator.

On average, a full-size family home will use 24 kWh per day in the warmer months, and 30 kWh per day in the cold season. The house can run directly off solar PV when the sun is shining, but here are the factors to consider for overcast days:

  • Battery storage is 15 kWh.
  • Batteries experience on average .5 charge cycles per day during the summer period and one charge cycle per day during the winter period.
  • Batteries cost $15,000 and are guaranteed for 3,000 charge cycles which equates to a battery lifetime of 12 years. This averages out to $1,250 per year.
  • Generator cost is $15,000; with limited run time it should last approximately 30 years, resulting in an annual cost of $625.
  • On average, the generator needs to produce 15 kWh per day during winter. The generator can do this with 1.5 L used vegetable oil or biodiesel: 1.5 L x 150 days = 225L x $0.60 per litre = $135/year.

Total annual costs

  • Cost for bio diesel approximately $0.60 per litre = $135 per year
  • Generator cost amortized over 30 years = $625 per year
  • 6 kW solar array and inverter $15,000 to last 50 years or more = $300 per year
  • Batteries amortized over 12 years = $1,250 per year

Total = $2,310 per year. We conservatively estimate that this is 50% less than what most full-size family homes cost to keep heated and cooled when connected to the grid.

Interested to know more?

We’re happy to answer questions about how to take your home off-grid, particularly if you’re building new and want to know the best decisions to make upfront to maximize energy saving potential. Give us a shout today.

Related reading:

Going Solar: the EkoModel Home
Your House Needs a Solar Engine, and We’ve Got It

 

Ottawa PassiveHouse Newspaper Article

Leave a comment

Our company was fortunate to be included in an amazing article in the Ottawa Citizen newspaper written by Patrick Langston.

The article ‘Comfort is key in a PassiveHouse’ discusses how true energy-efficient homes are more comfortable &, ironically,  actually save people money! Passive homes are prevalent in Europe but not well known in North america for some reason. We believe if more people knew of the cost saving benefits of a passivehouse, they would dominate new construction in North America especially here in Canada. By now, we can all appreciate utility costs are rising at exponential rates & who can afford this? We believe the rising operational costs of a home are unsustainable and passive homes are the answer to the future of home building.

You can read the full article here – Ottawa PassiveHouse Newspaper Article 

Building outside the box

An ultra-energy-efficient-home-in-a-box? Not quite, but an Ottawa custom home builder is offering a kit for those wanting a passive house, one so efficient that it requires only ten per cent of the energy needed in a conventional dwelling.

EkoBuilt, which has been building log homes since 2006, now sells Eko PassiveHouse kits in a variety of styles and sizes. The kit consists of the weathertight shell including cladding, doors and windows, and insulation. Buyers can arrange their own construction or contract with EkoBuilt to erect the shell and install wiring, plumbing and other elements.

A passive house achieves energy efficiency through an exceptionally tight building envelope, orientation, shading and other strategies. Benefits include not just lower heating and cooling bills but increased comfort — consistent temperatures from room to room, for example — and superior air quality.

The EkoBuilt line, which is certified by the International Passive House Institute, consists of a dozen different plans. They range from the one-bedroom Calendula at 624 square feet to the 2,152-square-foot Stonecrop with three bedrooms and a loft/fourth bedroom on the second floor.

Exteriors feature wood, fibre cement or steel cladding while interiors have exposed timber post-and-beam construction. Main living areas are generally open concept. Walls and ceilings, insulated to R-54 and R-62 respectively, use a combination of rock wool insulation and expanded polystyrene. Heating and cooling is via an air-to-air heat pump.

Prices vary. The Foxglove, a 1,424-square-foot home with three bedrooms and two baths, would cost about $318,665 start to finish including the kit, wiring and plumbing, interior finishes, and construction costs. The lot, hydro hook up and some other expenses are extra. (Note: this article is several years old and pricing is not current. Please refer to our energy efficient home plans page.)

EkoBuilt’s passive home kits come in a dozen different plans, including the three-bedroom Foxglove.

EkoBuilt co-owner Paul Kealey says “the time is right” to introduce the company’s passive home line. He believes recent energy-efficiency upgrades in the building code and general awareness about energy conservation is spurring interest in passive homes, a concept that originated in Germany in the 1930s, spread internationally, and is now entering, albeit gradually, the North American market.

“The passive house will revolutionize the housing industry,” he says, adding that government incentives would aid that revolution. That’s in part because a passive house costs five to 10 per cent more to build than a conventional home. Buyers, alas, tend not to think long term when it comes to operating costs such as a passive home’s payback in energy savings, not to mention reduction in greenhouse gases.

Other Ottawa-area firms offer passive house design and construction services. Arca-Verde Architects, for example, has projects in Wellington Village and Westboro. The former will be a passive house while the latter incorporates passive concepts.

Both will include salvaged metal cladding and cisterns for rainwater collection. They’ll also be net zero-ready (electricity-generating panels can be installed later) and designed for aging in place. The Westboro project is being built by Ottawa green builder RND Construction.

VERT plan.design.build is also involved in passive houses, and Homesol Building Solutions is the design consultant on over 20 passive homes being built in Ontario and western Quebec.