What are zero-energy homes and are they worth it?
With a new year around the corner and increasing news about climate change, we thought it would be appropriate to talk about net-zero; which is a home that nets zero energy-cost by the end of the year. Net-zero homes are the newest buzzword for highly efficient “green” homes. It is incredibly innovative and indeed fashionable - but is it affordable? More importantly, is it even worth it? We will be explaining exactly how net-zero works, net-zero retrofitting existing homes, and the costs.
What Makes Net-Zero Different?
Some homes can achieve zero energy costs by covering their roofs with excess solar panels and windmills, but this often is extremely expensive to install and maintain. Additionally, it often is not aesthetically pleasing. Old homes that are renovated for zero energy can also result in a lot of "wasted" energy. These retrofits on existing homes often have difficulty paying off. In fact, it may take 20 years or more to pay off renovations like these.
Net-zero eliminates some of these problems.
A real net-zero home is built from the ground up with the intention of cost and energy reduction in mind. First, the structure is designed with highly insulative walls and windows. These walls and windows are combined to create an air-tight home, which decreases energy loss. With an air-tight seal, it takes very little energy to heat or cool a house - this means far fewer solar panels are needed on the roof to create a sufficient energy source.
Retrofitting a home to become airtight can be extremely expensive, often making it not worth it. The cost of insulating an older house also depends upon the climate zone. Ohio is in Zone 5, requiring a more cold-resistant material. To be effective, "net-zero" should be planned well in advance of building a new home.
Will it pay off?
One of the most interesting features of net-zero homes is that they are still connected to the local power grid. There are a couple of ways that these houses reduce cost:
Batteries: Net-zero homes sometimes store unneeded energy produced from their solar panels in batteries. This energy can be conserved for cloudy days or when outdoor temperature becomes turbulent. Batteries also allow for the storage of electricity when energy costs are low. When building your home, it is estimated how long it will take for energy savings to pay off compared to purchasing energy from the utility grid. If the estimated cost of generating your own energy becomes higher than the grid's price at any time, you can store the energy for later and purchase from the grid instead. This shortens the amount of time that will be needed to return on your investment in zero energy.
Selling energy: Some local grids allow net-zero homes to sell their excess energy. This can reduce the price of batteries while providing similar returns. On very sunny days with mild temperature, you may find yourself with electricity to spare - this electricity is fed into your local grid, who then compensates you for the energy, thus expediting the return on investment. During an emergency or cloudy day, power can always be purchased from the grid if you didn't install batteries.
Pros and Cons
Net-zero can provide a clean and comfortable home. The insulation and air-tight features reduce drafts and temperature fluctuation. Additionally, outside noise is highly reduced. You are also leaving a minimal carbon footprint!
Unfortunately, this can all be very expensive, and many utility companies still do not support some of the features that make net-zero "real net-zero." Some areas also make net-zero less feasible, like living in the woods, for instance. The more shade - the less energy production. With increasing concerns over climate change and renewable energy, it is likely that these installments and innovations will become more affordable at some point in the future. For now, the most feasible option is to learn about ways to reduce your current energy consumption.