Powerwall Experience in Texas with "Cost Savings"

[JES2]

After reading some of the entries from other users, I thought I would add my experiences on utilizing my two Powerwall 2 units along with my 8.33 kw Solar City panels (from 2013), and my Tesla 3. I installed the Powerwalls earlier in the 2018. The Tesla 3 arrived in August.

I live in Dallas, and Texas has quite a bit of wind power (around 25 GW). A few retail providers offer electricity free at night, since the wind price is so cheap. Reliant Energy charges 20 cents per kwh during the day hours (6 am to 8 pm) and free from 8 pm until 6 am.

I have set up the Powerwall to Cost Savings, and have set peak power from 6 am to 8 pm. I wait until after 8 pm to charge up the Tesla 3. So far, the results have been great. I am averaging about 26% on the days I charge the Tesla:

However, during the peak hours, I am getting pretty close to zero energy from the grid. I would point out that this was mostly a cloudy day. Having the Powerwalls were able to fill the gaps in which solar energy was not producing (early morning and early evening.)

Generally, I have been using all of the solar energy I produce during the day, or using it to charge up the Powerwall. The amount I have sent back has been negligible. I'm also getting great value for not paying any energy at all to my electric retailer. Below shows about 45 kwh at night, all no charge when I charged my Tesla and ran a dryer for a few hours.

 

[bigroo42]

@JES2 i'm considering solar and would love any resources you could share for me to research online. I hate to 'trust' the solar providers with their information as they are obviously trying to sell me something. thanks in advance!

 

[bob_p]

In Houston, we shifted to a Free Nights plan several weeks ago - free electricity between 9PM to 9AM and $.20/KWh between 9AM to 9PM.

During most days, we are 100% solar/PowerWall power during daytime. Only during days with significant cloud cover, like yesterday when we had heavy rain storms most of the day, will we use grid power during the day.

Before shifting to the plan, I reviewed the Smart Meter data (power provided by the grid in 15 minute increments) over the last 5 months (since our solar panels were installed) and estimated we'd reduce our electric bills by about 50% with the Free Nights plan (beyond the 50-60% reduction we already had with the solar panels). And now that I've changed scheduling on a few power-hungry devices (like the pool pumps) to run during the Free Nights period, we should save even more under the new plan.

Wouldn't be surprised to see the utility companies exclude homes with battery storage from the Free Nights plans at some point, because they aren't expecting those customers to generate almost 100% of their own energy during the days, and end up paying little to the utility companies each month...

 

[miimura]

Wouldn't be surprised to see the utility companies exclude homes with battery storage from the Free Nights plans at some point, because they aren't expecting those customers to generate almost 100% of their own energy during the days, and end up paying little to the utility companies each month...

In California, Minimum Monthly Charges used to be about $5/mo. Around 2017 or 2018, they were increased to about $10/mo. This was another way for the utilities to get in a dig at solar customers that just pay the minimum many months of the year. It wasn't discriminatory though, they increased the minimums across the board.

Increasing minimum charges or increasing fixed monthly fees will become more common as distributed generation becomes more common.

 

[wjgjr]

Increasing minimum charges or increasing fixed monthly fees will become more common as distributed generation becomes more common.

Yeah, I think this is inevitable. For now, the cost is essentially passed on to other customers who are helping subsidize clean energy, which is arguably a reasonably public policy decision, but there potentially comes a point where that subsidy would be unreasonably high. Hopefully, though, the cost of solar will continue to decline more quickly than any increased fees. It will still potentially be an issue for those of us already with solar, depending on how much we are grandfathered into existing arrangements.

Around here, there is a $8 monthly account fee for everybody on the standard plan.

 

[garrett5688]

@bob_p @JES2 when using the cost saving option, and setting peak for basically all sunlight hours, does it prioritize powering home and charging the PW to 100% before sending any excess energy to grid? reading other examples, it seems TEG will send solar to the grid during peak, but that is the opposite of what i would want.

(also in TX and looking to switch to a free nights plan)