A net zero home is designed to produce as much energy as it consumes, and in an era where sustainability and environmental consciousness have become paramount, the concept of net zero living has not only become popular, it’s becoming part of British Columbia’s municipal building code.

According to Bruce Ralston, Minister of Energy, Mines and Low Carbon Innovation, “More and more British Columbians are switching to electric vehicles to save on fuel costs and reduce air pollution. Through CleanBC, we’re working with our partners to expand our EV charging network across the province, make it easier for drivers to go electric and put B.C. on the road to a clean energy future.”

One of the essential components of a net zero single-family home is a robust electric vehicle (EV) infrastructure, with one or more EV charging stations, part of an energy system that includes solar renewable energy and bidirectional energy exchange between the house and the grid.

In this article, we will explore steps and important considerations for establishing an efficient EV infrastructure when designing and building your net zero home or retrofitting your existing house.

Establishing your electric vehicle needs?

The starting point is determining how many electric vehicles you intend to own and accommodate. If your family already has one or more EVs, and you will host guests, you’ll need to install enough charging options for all of the vehicles.

Different electric vehicles could have varying charging requirements. You may decide that you need two Level 2 AC charging stations in the garage for overnight charging and one Level 2 or Level 3 station on the driveway for teens or other family drivers and guests.

Driving habits are also a consideration. If there will be long commutes into the city during the week, faster charging options will ensure that your vehicles are adequately charged overnight or during the day.

It’s also important to plan for future expansion. More drivers in your circle are going to be switching to EVs over the next few years. Charging vehicles is becoming part of modern life, and dinner guests might have to cancel to charge their vehicles for work the next day unless you have a driveway charging station available to them.

If you have children who will be reaching driving age, or you’re considering multi-generational living, the best time to build the electrical infrastructure for your potential future needs is during your net zero home build or retrofit.

What are the right charging stations for your needs?

Once you and your design-build contractor have assessed your electrical vehicle needs, present and future, it’s time to choose the right type of charging station(s). There are three primary types:

Level 1 charging uses a standard 120-volt AC/60 Hz household outlet. The charging cable for this will typically be included with your electric vehicle. It’s the slowest charging option available and will give you roughly 6.5-8km of driving range per hour of charging. It’s suitable primarily for overnight charging and for local driving.

Level 2 charging stations operate on a 240-volt AC circuit and offer significantly faster charging speeds than Level 1. You’ll get about 32-48 km of driving range per hour of charging. Level 2 charging will accommodate your daily charging needs for local driving, and can fully charge most EVs overnight, suited for commuting, business driving or shopping trips to the city.

Level 3 rapid charging is the fastest charging option, and this is typically what you’ll find at public charging stations along highways and shopping plazas. DC fast charging offers 96-129km of driving range with just 20 minutes of charging. Level 3 charging is very convenient for long trips, but due to its higher cost and power requirements, it hasn’t been installed in residential settings as often.

Level 2 charging stations are typically the best choice for net zero homes, offering a good balance between charging speed and energy efficiency. These systems are easy to integrate into your home’s renewable energy system as well.

Choosing your charging station location(s)

Convenience and accessibility are important considerations when choosing the optimal locations for EV charging stations. Garages are the most popular, offering protection from the elements; and they are perhaps the most convenient place for nightly charging. You’ll want to ensure that your single or double garage is wired with the necessary electrical capacity to support one or two charging stations.

If your home doesn’t have a garage, or you need an additional charging option, a driveway charging station could be perfect. Whether you just need a quick 20-minute charge before heading back out, the teens will be charging their vehicles overnight, or you have guests staying over, a weatherproof outdoor station with retractable charging cables or cable reel is a very convenient addition.

Designing the electrical infrastructure

To support the electrical vehicle charging stations in your new net zero home or retrofit, your design-builder and electrician will give careful consideration to the building’s electrical infrastructure.

The capacity of your home’s electrical panel must be able to support the additional load from the charging stations. If it’s a retrofit, you may need to upgrade to a larger panel to ensure safe and reliable charging. Each charging station should have its dedicated electrical circuit. Your builder and electrician will determine the electrical load and circuit requirements and confirm that the wiring and circuitry are up to local code.

Using solar power to charge your electric vehicles

Most days, your net zero home will be generating its electricity, and you’ll want to integrate your electric vehicle charging stations with your solar panel system. You’ll want to be able to charge your EV using clean, renewable energy, generated on-site, thereby reducing your carbon footprint and energy costs. Unfortunately, during the night there’s no solar energy available, and clouds, shade, hot temperatures, rain and snow can minimize the amount of solar energy that reaches solar panels. During those periods most net zero homes draw power from the grid.

Smart charging stations or panels can optimize energy usage and reduce costs. On February 27, 2023, BC Hydro submitted a proposal for a new optional time-of-day rate for residential customers. With the new rate, customers will get a credit of 5 cents per kilowatt hour (kWh) for electricity used overnight (11 p.m. to 7 a.m.) and be charged an additional 5 cents per kWh for electricity used during the on-peak peak period (4 to 9 p.m.).

Your smart panels or stations can be scheduled with solar power charging sessions during production hours, or to switch to charging during off-peak hours when the grid’s electricity rates are lower. An energy monitoring system tracks the energy production from your solar panels, the energy consumption of your home, and electric vehicle charging. The real-time data is then used to effectively balance energy loads. To minimize grid dependency you’ll prioritize charging your EVs during periods of high solar production.

Your net zero designer-builder will work closely with the professional solar installer to assess your needs and design a system that perfectly meets your family’s needs. To determine the size of your solar array for EV charging your team will consider your electricity consumption for both your home and EVs.

Solar + net metering + storage

BC Hydro offers a net metering program that allows you to power your home with renewable energy, and be self-sufficient while having the flexibility to rely on their power grid when you need it.

But what happens if there’s a prolonged power outage? When powering both home and electric vehicles, many net zero homeowners have been investing in battery storage as well. Your home’s solar inverter converts DC electricity from your panels into AC power for your home and EV charging. With what is sometimes referred to as ‘the Solar Energy Trifecta’, your smart panel can keep your battery storage system topped up, while also sending any surplus energy to the grid.

The grid-tied system allows you to sell surplus energy back to the grid, while an off-grid battery storage setup would make you fully self-sufficient. Having both backup energy solutions offers a unique advantage, particularly when both your home and vehicles are relying on electricity. With provinces with time-of-use (TOU) rates, and demand charges or net metering compensation rates below retail rates, energy storage systems have the potential to save you money.

This means that as a distributed solar photovoltaics (PV) owner, you can store electricity during times of abundant solar generation and withdraw it from the storage system when grid electricity rates are higher. You could potentially consume electricity from the grid during periods when solar production does not meet demand and/or electricity rates are low, but draw it from your battery storage during peak hours, when rates are high.

Are there any incentives?

Yes, currently we have the B.C.’s EV Charger Rebate Program, with the $250 smart EV charger rebate available. This program is part of the CleanBC initiative to make clean transportation more affordable and accessible for British Columbians.

When available, single-family homes, row homes, duplexes or townhouses can get a rebate of up to 50% of the purchase and installation costs of an eligible Level 2 EV charger, to a maximum of $350.