Zero Energy Ready Home Certification

The Legacy House got its U.S. Department of Energy Zero Energy Ready Home (1) certification (dated August 1, 2019). That’s a recognition of the quality of the work done to build an efficient home. A standard new home has an HERS Index (2) rating of 100 or thereabouts. The Legacy House came in at 17. Lower is better, of course.

The certificate projects an annual energy cost of $950 and annual electricity savings of 27,934 kWh. Estimated CO2 reduction is 24.9 tons. We will watch it and see how accurate this information is.

  1. https://www.energy.gov/eere/buildings/zero-energy-ready-homes
  2. https://www.hersindex.com/

Electricity Use

We have four months’ data to give us some idea how the Legacy House solar plant, seen above just after installation, is working.

May 2019 — $46.48, 731 kWh delivered, 416 kWh to grid, 315 kWh net.
June 2019 — $20.40, 617 kWh delivered, 544 kWh to grid, 73 kWh net.
July 2019 — $9.50, 488 kWh delivered, 536 kWh to grid, -48 kWh net.
August 2019 — $16.48, 619 kWh delivered, 577 kWh to grid, 41 kWh net. 

It appears that we are getting a bit less than 85% of our power from the garage roof panels. That’s great, but a bit more than we really want. Unless one builds off-grid, AEP Ohio expects net-metering users like us to buy some power to pay for grid maintenance. That’s fine.

Keep in mind that the numbers above relate to the house and the electric car in the garage.

Drip Irrigation

At the Legacy House we are trying to be responsible about the use of energy and water. We have started installation of a drip irrigation system (1) for the lawn-free landscaping.

The drip lines in the image above will be covered by two to three inches of mulch. They are uncovered now until we are sure everything is working properly, as it seems to be.

There are long lists of advantages and disadvantages to drip irrigation. For us low water usage, low initial cost, and better weed control were the principle considerations.

  1. https://en.wikipedia.org/wiki/Drip_irrigation