Battery Installed

There have been a lot of technology advances in energy storage since our house was built.

Back in 2012 battery technology was generally only used for short term UPS and off grid systems.

Lithium-ion batteries were being used in appliances but nothing had been developed for home energy storage. In 2015 Tesla released the first generation of its Powerwall, this was an indication of what had been happening with battery development. At about that same time Panasonic and solarcity NZ started working together to design a fully a rechargeable lithium-ion battery to store energy for load shifting, backup power and self-consumption of solar power.

We were keen to learn about how a battery might play a role in the energy management of the Zero Energy House. A beta version of SolarCity’s new battery was installed in our house in September as part of a trial.

We are expecting that it will help us reduce the amount of energy that we export to the grid, and provide us backup in the unusual event of a power cut in Pt Chev. Overtime we hope that we can use it make the most of time of use energy pricing. Coupled with the load control of our hot water and electric vehicle charging, we are expecting big changes in how we use power. We expect that the viability of solar for households will be increased with these technologies.

We’ll give you some feedback on how it’s performing in a month or two.

There was a little bit of media coverage, but unfortunately the reporters didn’t pick up in the details of what we were discussing. Newshub, Stuff, solarcity’s press release.

There has been some good coverage of the potential for solar power and energy storage lately.

• Vector put out a report saying solar power and battery storage was an easy and cost effective way to improve a homes energy resilience.

• The Productivity Commission said solar, along with wind and geothermal, will be part of NZ’s portfolio of renewable generation needed to meet growing demand.

• Greenpeace unveiled a plan called Solarise New Zealand that would see half a million homes solarised over the next 10 years with money currently being used to subsidise the oil and gas industry.

Reflections four years in.

Its nearly four years since we move in... . The most significant change during this time is that there is now four people and a dog living here. This of course has had many implications, but as the house is concerned it does effect how we use it, the resources we consume (and the time I have to finish the house...).

Over the next few months I will be writing a few blog posts on lessons learnt during the building (long overdue), and how the house has been performing.

I also would like to convey how the house has ceased to be a project, a technical creation that we worked to design and build, and how it has transitioned to being a home.

Our philosophy during the design process was to use standard NZ construction methods where we could, tweaking them to improve how the house performed. Through this we hoped to demonstrate that with a bit more attention to detail and a little bit more up front cost we could improve how comfortable and healthy our home was, while reducing the overall costs.

The topics of future blog posts are intended to be:

• Year 3 performance (comfort, energy and water).
• Data. At Evident we have been working on a new data system which we'll be using to display live and historic data on the ZEH website.
• Timber framing. Our timber framing solution is one of the areas we get the most question about.
• Joinery. The issues we have had with our joinery material selection and paint work.
• Landscaping. It was all about the building, but the garden has really made it.
• Consenting. Issues with the resource and building consent process.
• Energy. We're still zero energy, but why has our energy use increased?
• What next. What would we do differently, what might we add in the future.