Net Zero Overview — Hovland Consulting LLC

Why go net zero?

In January 2022, just miles from where we live and work, the Marshall Fire erupted in Boulder County, and with hurricane-force winds and extremely dry terrain, the fire burned over 6,000 acres and destroyed 1,000 homes and businesses in Boulder County. Each year as Colorado, Maui, and the world see increasingly hot and dry conditions, we are reminded just how critical it is to starve the path of climate change as quickly as possible - starting today.

Fighting fires in Boulder, Colorado (December 30, 2021, Photo by Ralph E Burns, Middle Fork Fire, truck from Boulder Mountain Fire Protection District)

Our team at Hovland Consulting (HC) understands the urgent need to transition to locally-sourced clean energy for our homes and transportation. Only by rapidly slashing greenhouse gas (GHG) will we avoid the worst impacts of climate change. Fortunately, the technology is here today to affordably increase building efficiency and power our homes and businesses with renewable energy - and electrify everything.

In our work at HC, we spend our days digging into data about the climate crisis, assisting our clients in developing tangible solutions, and facilitating global learning. But the work goes deeper - we realize that each of our homes and transportation modes represents a huge opportunity to decrease carbon emissions. Val, founder and principal at Hovland Consulting made the personal commitment to achieve net zero as quickly as possible by driving electric and electrifying everything in her home - heating, cooling, hot water, and cooking. The following 2-part blog series details the background and steps Val took toward net zero.

What is net zero?

Net zero refers to using (or producing locally, in my case solar) as much clean energy to offset a building or person’s energy consumption. The ‘net’ aspect means that over a year you produce the amount of electricity you use in a clean/climate-friendly way, while still tied to the power grid. Remaining grid connected usually comes into play in cold climates, where more solar is produced in the summer and more electricity comes from your local grid in the winter to heat your home.

Chart 2. Solar generation at Val’s house, consumption (kWh), with net as the difference between the two.

The charts at the right show data from Val’s home in Boulder Colorado in 2020 in aggregate (Chart 1) and by month (Chart 2). The yellow solar is generation (higher in the summer months), the brown is the home usage (higher during the winter in Colorado), and net is the difference between the two.

A summary of the process. To go net zero, there are a few main steps:

Electrify all house uses. Switch all fossil-based uses – appliances (cook stove, clothes dryer), heating, air conditioning, and hot water to electric. Electric heating and cooling are the largest energy demands (see Chart 3), followed by hot water. To reduce the overall heating/cooling loads as much as possible, often the insulation will be increased and the building will be air-sealed.

Electrify your vehicle, and where possible walk, bike, or take sustainable transit.

Power with renewables. Use renewable energy to power all these needs. The most common and accessible sources of renewable energy are purchasing renewable energy credits from your utility, rooftop solar panels, or membership in a solar garden.

Chart 3: Detailed energy consumption, broken down by appliance, compared to outside temp (F).

Here are some lessons learned from our experience

Some “cool” aspects of net zero, like solar, should not come first - instead, wait as you take a systems approach and determine your power loads over a year. By first electrifying all appliances, increasing the efficiency (thermal and electrical) of your home, and going with an EV, the solar installers (or you) will be able to more accurately size the required solar system size.
Heat pumps are a double win. Air source heat pumps provide heating and cooling in one package. You don’t have to pay for two systems.
Observe your home’s energy consumption across an entire year or more, as the cycles of cold winters and hot summers highly influence the steps you will take to make your building net zero. Look at both gas and electric use. See Chart 3 above for the variation Val saw in Colorado.
Take one step at a time. While this may seem like a daunting amount of work to do, it can be done one step at a time. Even without the solar offset, a fully-electric house produces a declining amount of climate emissions, as wind and solar are displacing carbon-intensive coal and other fossil fuels in the power grid.
Tell your story - engage in social learning. Early adopters can play a strong role in inspiring others to follow suit. We have influenced a number of people in our peer groups to undertake similar projects. One challenge with home electrification is, from the outside, an energy-efficient home will not appear any different than a regular home with a large solar array. Therefore it is important to share lessons learned and talk about your success in achieving net zero or near zero with your friends, family, and neighbors.
You can do this too! Now, more than ever, it is easier and less expensive to go net zero. Much of the technology presently used may be acquired at local hardware stores. If you want to go net zero, check out our upcoming blog with actionable steps you can easily take toward net zero.

What’s Next?

In our upcoming blog, we will go into more detail on the steps we did (and you can) take toward net zero including:

Heating, cooling, and hot water with heat pumps (air source in our case)
Appliances: Updating electrical appliances (especially induction cookstoves) and lighting fixtures
Building: Updating insulation and air sealing
Car: Drive electric
Solar electricity to run it all
The finale: Cut the gas line!