What Are the Steps You Can Take Toward Making Your Home Net Zero Energy?  

I don’t know anyone who doesn’t like the idea of saving money, which will happen when you convert your home to “net zero energy.” So, what are the steps you can take to get there?

Net zero energy” means that your home generates more energy than it consumes. With “net metering,” your electric meter runs backwards when your solar panels generate more electricity than you’re using (on a sunny day), then runs forward at night, resulting in zero (or less) net consumption of electric power.

Solar power gets more affordable every year. When I purchased my first 10-kW solar photovoltaic system 15 years ago, the cost was over $60,000, but Xcel Energy gave a rebate of $4.50 per watt, so I got a check for $45,000 from the utility, reducing my net cost to $15,000. Nowadays that same system would cost as little as $15,000 with no Xcel rebate but a 26% federal tax credit.

While you can generate your own electricity, you cannot generate your own natural gas, so terminating natural gas service is key to achieving net zero energy. This involves some major system changes if you are currently heating your home and your water using natural gas, cooking with gas (including with a gas grill) and have a gas fireplace.

There are electric alternatives to all of these uses of natural gas, and you’ll appreciate that eliminating natural gas also eliminates the possibility of a gas explosion and of carbon monoxide poisoning (unless you have a gas powered car).

Heating your home with electricity used to mean installing baseboard resistance heating units in each room, but that is so 20th century. Nowadays electric space heating is done far more efficiently (and evenly) using heat pumps.

Gas forced air furnaces and water heaters are considered to have a 15-year life expectancy, so when yours fail, think of that as an opportunity to adopt heat pump technology for both functions. And a heat pump eliminates the need for a separate A/C unit, since it heats and cools.

Gas furnaces and water heaters generate heat by burning gas. A heat pump moves heat, similar to what A/C does. (How heat pumps work) It cools your home by moving the heat out of your house. If you put your hand over the external compressor unit while it’s cooling your home, you will feel the heat that was moved from inside your home. In heating mode, the process is reversed, and the heat pump moves heat from outdoors into your house. It may surprise you to know that when it’s freezing outside there is actually heat that can be moved from outside to the interior of your house, but it’s true. (Heat pumps work in extremely cold climates) Our office has been heated solely by heat pump since November 2017, and ever since there has never been a day when the system failed to keep our office at 70°F or warmer.

A simple one-unit 12,000-BTU, 29.3-SEER ductless mini-split system from Fujitsu can be found online for $1,961. That’s a small unit, suitable for one room or a garage (a great application!). For our office, we bought a Mitsubishi system in which a single compressor drives three separate wall units, each with its own thermostat.

A heat pump water heater (which I installed at our home) has the compressor built into the unit, above the tank. You can feel cool air emitting from it when it is heating water. I suggest putting it in a wine cellar where it’ll keep the room cool without buying a separate A/C unit.

For cooking, you’ll be amazed and delighted by the induction cooktops that are now widely available. I saw them used on a cruise ship for both cooking and warming surfaces, and the chefs loved them. (Modern cruise ships have eliminated natural gas because of the fire hazard.)

An all-electric home will, of course, demand more electricity, but Xcel Energy now allows you to install enough solar panels to generate double your electrical usage over the prior 12 months. That is more than enough to cover your new electric space heating, water heating and cooking needs, with capacity left over to charge an EV, too.

An important first step in pursuing net zero energy for your home is to reduce your need for energy, and the easiest and cheapest way to do that is to improve your home’s insulation. I had Dennis Brachfield of About Saving Heat blow cellulose insulation into the exterior walls (not just the attic) of a 1940s bungalow I owned, and I was astonished at how much more comfortable the house became. Even if your exterior walls have batt insulation in them, there is still space in the walls to blow in cellulose. (How to insulate an old house)

I learned something interesting from that experience. We all know that walls can radiate heat, such as a brick wall in bright sunlight. Well, walls can also radiate coldness, or suck heat. The air temperature in my bungalow before and after blowing in insulation was the same, but I felt warmer and burned less gas.

You can go beyond improving the insulation of your exterior walls and attic. There are numerous places that allow cold into your home, especially around your windows. Whether or not you install triple-pane Alpen windows, as we did at our office, caulking around the window frames and elsewhere can reduce the energy needed to heat your home.

A blower door test done by a contractor will identify the air leaks in your home. Insulating your attic with blown-in cellulose and your crawlspace with plastic sheeting will also reduce your home’s energy needs whether from gas heating or your new heat pump. (Insulating crawl spaces)

Of course, many homes, especially in older neighborhoods, can’t benefit from solar power because of shading from trees or insufficient south-facing roof area, but you can purchase community solar. (This is also a good solution for condos which have no roof at all.)

The way community solar works is that you invest in solar panels that are part of a solar farm in some distant pasture. The electricity generated by your panels in that remote location is credited to the electric meter for your home or condo. One advantage of community solar is that when you move, you only need to change which meter gets credited with your solar production.

Other ways of reducing energy use include replacing CFL or incandescent light bulbs with affordable LED bulbs and “daylighting” your home or office. (Batteries + Bulbs sell 8-packs of 60W LED replacement bulbs for $6.49, tax included, after $15 instant rebate.) We have “sun tunnels” in our home and office to bring daylight into interior spaces. In fact, on a sunny day we don’t need to turn on any lights in our office. It’s great— and saves energy. We had Design Skylights of Evergreen install Velux sun tunnels at both home and office.

Would you like one of us to visit your home for a private consultation about the sustainability possibilities in your home? Email me at Jim@GoldenRealEstate.com.

All-Electric Homes (and Buildings) Are Central to Mitigating Climate Change

As much as we Americans love our gas fireplaces, gas ranges and gas grills, we need to recognize that the move to an all-electric home, with the electricity being generated using minimal fossil fuels, is central to the goal of mitigating the effects of climate change.

And it can be a good future, especially if you’re able to generate all the electricity that your home and cars use.

That’s the future Rita and I have created for ourselves. We have 10 kW of solar panels on our Golden home, enough to heat and cool our home and charge our two electric cars. Our forced air furnace only burns gas when the outside temp dips below freezing. Otherwise, a heat pump provides all the heat we need. And recently we replaced our gas water heater with a hybrid water heater that heats all the water we need using its built-in heat pump. It has a standard electric heater coil in case we need faster recovery.  (We never have needed faster recovery.)

Yes, we still have a gas cooktop and gas fireplace, and our BBQ grill is plumbed with gas. I can picture us moving to an induction electric cooktop, electric fireplace and electric grill, but for now we comfort ourselves with the knowledge that we have drastically reduced our carbon footprint and our monthly energy bills with the use of heat pumps for heating, cooling and water heating, as well as by driving EVs.

A December article on axios.com reported that some progressive jurisdictions are now banning gas hookups in new residential and commercial construction. According the article, 40 California municipalities, starting with Berkeley in 2019, have banned the installation of natural gas service in new construction.

The most common argument against this anti-natural gas trend relates to the cost of electric heating vs. gas heating, but the people who make that argument are probably thinking of conventional resistance heating, such as baseboard electric heating.

Resistance heating is similar to your kitchen toaster, sending electricity to a coil causing it to generate heat.  There is a more efficient way to heat, however, which is to use a heat pump. A heat pump moves heat instead of generating heat, and the cost is as little at one quarter that of resistance heating for the same BTU (heat) output. Here’s a article comparing the two kinds of electric heating.

Moreover, a heat pump can provide both heating and cooling, merely by reversing the direction in which it moves heat, replacing both the gas furnace and electric air conditioning unit which most of us have in our homes.

Another argument against increased electrification is that electricity is itself created by the burning of coal and natural gas. The current fuel mix of Xcel Energy in Colorado is 36% natural gas, 32.5% coal, and the rest renewable energy (mostly wind). The company’s goal is 55% renewable by 2026 and 100% “carbon-free” by 2050, so it makes sense to start now replacing gas appliances with high efficiency electric ones such as heat pumps.

Keep in mind, too, that we can generate our own electricity at home and on our office buildings, taking advantage of “net metering,” paying only to be connected to the electric grid. With net metering, Xcel’s grid functions like a battery, taking excess electricity from our solar installations during the day and delivering it back to us when the sun goes away — or when our solar panels are covered with snow!