{"id":45386,"date":"2015-05-09T08:35:27","date_gmt":"2015-05-09T06:35:27","guid":{"rendered":"https:\/\/www.sonnenseite.com\/energy\/what-the-tesla-powerwall-battery-means-for-households.html"},"modified":"2015-05-09T08:35:27","modified_gmt":"2015-05-09T06:35:27","slug":"what-the-tesla-powerwall-battery-means-for-households","status":"publish","type":"post","link":"https:\/\/www.sonnenseite.com\/en\/energy\/what-the-tesla-powerwall-battery-means-for-households\/","title":{"rendered":"What the Tesla Powerwall battery means for households"},"content":{"rendered":"

Since Tesla dropped the Powerwall, numerous claims have been made about what this means for households and the grid, ranging from ‘The Powerwall changes everything<\/a>’ to why it’s ‘just another toy for Rich Greenies’<\/a>.<\/p>\n

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In order to guide the economic discussion, I’ve created a simple calculator which allows people to investigate for themselves the household economic impact of solar plus batteries at Tesla prices!<\/p>\n

To access calculator, click on this link. It will download to your laptop or computer. You will need Excel. Simple Solar plus battery economic calculator<\/a>.<\/p>\n

It’s free to download, use, and adapt for non-commercial purposes. Ensure you read the model limitations and assumptions before you begin, and interpret results accordingly.<\/p>\n

Example – A working household in Sydney<\/span><\/strong><\/p>\n

Here is a sample output for a household in Sydney with 12kWh daily consumption, who install a 4kW solar system with 7kWh Powerwall. They have a typical ‘working household’ load profile with some controlled daytime loads such as washing machine and dishwasher. The energy flows in the charts below are based on an average day – that is with average solar output and average electricity consumption.<\/p>\n

Summary<\/strong><\/p>\n

The most notable impact is that the entire evening peak demand is covered by the battery. With solar and battery combination, the households source 92% of their energy from solar, versus just 36% with solar only. The day’s grid cost for this household is just 4c (excluding fixed costs) with solar and battery installed.<\/p>\n

With the 7kWh battery pack installed, the householder pays the equivalent of 30c\/kWh (levelised cost) for their solar and power, which for many households is at grid parity.<\/p>\n

At current prices obtained from Solar City ($US7160 for the 10kWh fully installed), if it were a straight numbers race, the optimal decision for this household, if their flat electricity tariffs is 30c\/kWh, is to:<\/strong><\/p>\n