By Bruce Naegel June 2018
All Electric Home, Dream delivered today
Why an All l Electric Home?
As the grid has cleaner electricity, the All Electric Home becomes more relevant. The electricity supplied to the Bay Area has very low carbon content. Cities like Palo Alto and those in the SVCE (Silicon Valley Clean Energy) (1) service area have carbon free electricity today. All Electric Buildings powered by carbon free electricity can approach or meet zero GHG targets. What does an all electric home look like? Is this an impossible dream? How expensive is the fully electric home to construct?
All Electric Home Features
Builder /developer/lessor Prabhas Kejriwal hosted an All Electric Open house in a new apartment complex at 430 Forest in Palo Alto, so it is possible. This apartment building has a large penthouse, ten 2-bedroom apartments and 2 town homes. It is LEED Platinum and features:
– Solar electricity supplied to the complex
– Electric Vehicle (EV) level 2 charger for each home
– Heat Pump water heaters in each home
– Heat pump space heaters
– Heat pump clothes dryer
– Fully electric kitchen including an induction stove
Two of the homes (one 2-bedroom apartment and the penthouse) were on full display. After the walk through, there was a presentation and a Q and A session. Hiromi Kelly (Program Manager for CPAU (City of Palo Alto Utilities (2) asked the questions. Builder / Developer / Lessor Prabhas Kejriwal provided the answers. The gist of the questions and answers is below:
Q and A Session
Hiromi started the Q and A section asking what started this project? Prabhas said he saw a need for this kind of construction and wanted to show it was possible and practical. By practical, he means one can have superior energy efficiency at the same construction cost as a home built to standard code.
One cost savings is the elimination of the gas lines. Gas lines are expensive. They can now spend the money saved on advanced heat pump technology.
Where did Prabhas get the knowledge to put this together? His answer? It is all out on the web. His wife chimed in and described his constant search for knowledge.
How did the builder and the city interact to get this building finished? Prabhas indicated the interaction with Palo Alto went well. Working with Palo Alto made it possible to construct this apartment building.
What about smart heat controls in the building? The Rheem brand Heat Pump Water heaters (3) (HPWHs can network to a NEST thermostat. The building does not have this integrated today. However, this is a future option.
Hiromi asked about the solar cells on the roof. Why is there a white reflective coating on the roof under the solar cell? This reflective coating and the spaces between the solar cells means electricity is generated from sunlight on both sides of the solar cell. This boosts output by 10%. (4)
A key question is how expensive it is to go all electric (no gas) Parbhas said this approach did not add to the construction cost of the building. Costs were offset by eliminating items like the gas lines.
Hiromi asked if the building took any longer to build than a standard home. Prabhas’s answer is no. The key issue is to line up the suppliers once the specifications are finished. While the construction techniques are a bit different (e.g. using SIPs as described below), the construction does not take longer.
Open House Vendor Display
The Open House had a Vendor Display for the components used for the construction. The Passive House organization was one of them. Passive House is a voluntary energy efficiency standard in use in Germany for over 22 years. Buildings built to Passive House standards can save 90% of the energy used for heating. Tens of thousands of homes have been built to this standard. See specifications here (5).
Better insulation is needed to achieve this level of efficiency. One of the components used at 430 Forest is SIP or Structural Insulated Panels. These panels have the insulation between two composite boards. Besides providing structure, they make the insulation easier and more effective to seal. Information here: (6) . Other vendors were there including Rheem, a leading supplier of water heaters and furnaces, including heat pumps. The solar provider Staten was also there (4).
We need more examples of houses in the Bay Area built to Passive House standard and all electric. With Passive House Standards, one can buy the minimum heating system that meets heating requirements. Examples that are more mid to lower market will prove how to make this work for a wide range of applications.
GTM recently published an article on All Electric Houses. There is more
information on that here. (7)
(5) https://en.wikipedia.org/wiki/Passive_househttp://(5) https://en.wikipedia.org/wiki/Passive_house
(6) http://www.sips.org/http://(6) http://www.sips.org/