Look at the link you posted. The recommended battery pack for that system is 62kWh (1284Ah * 48VDC). That is the equivalent of 6 10kWh Powerwall batteries.
Furthermore, the 10kWh Powerwall is not for solar or other daily applications; it's for backup.[1] A PV system needs to use the 7kWh batteries, thus requiring 9 for this system. That is $27,000 in batteries.
Now, on to the panels. The sizing of the system you posted indicates it assumes 5 Sun hours per day. Most of the US gets less than that; from the map on the site it looks like 4.3 is a good average for the US. Next, as the site clearly says when you run their off-grid calculator, you need to discount the Sun hours if you plan on using the system in the winter; they recommend knocking 1.5 off your yearly average. That drops most of the US to 2.8. That means the median house would need twice the number of solar panels in that set to cover all times of year.
Combined with the actual cost of Powerwall batteries, we are at $67,344. If you want to use the Pacific Northwest as your baseline (which someone opposed to solar would try to do) you approach the $98,000 for an off-grid system.
Look at the link you posted. The recommended battery pack for that system is 62kWh (1284Ah * 48VDC)
Oh look. It's $8k. So the total price is $28k.
62 kwh is over two full day's worth of electricity usage for the average US home. I actually think that's probably quite a bit more than you need. Two of Elon's batteries is 20kwh, which is about 2/3 of an average day's usage - enough to last most people the night, right?
Now, on to the panels. The sizing of the system you posted indicates it assumes 5 Sun hours per day. Most of the US gets less than that
$98k was in California right? According to this, Los Angeles gets 5.62. Manhattan gets 4.57.
Yes, and the sentence you quoted specifically said the $98,000 figure was using Tesla's batteries.
62 kwh is over two full day's worth of electricity usage for the average US home. I actually think that's probably quite a bit more than you need. Two of Elon's batteries is 20kwh, which is about 2/3 of an average day's usage - enough to last most people the night, right?
Wrong. An off-grid PV system requires a buffer to supply power during days with little to no sun. Two days is about right for most of the country; in some places I would size it larger because they are prone to multiple days of overcast conditions at certain times of year.
Furthermore, you completely ignored that I stated, supported by the link I provided to the Tesla page, that you are not supposed to use the 10kWh batteries for daily drain applications.
$98k was in California right? According to this, Los Angeles gets 5.62. Manhattan gets 4.57.
I didn't look into where the $98,000 was supposed to be located. I assumed they took the least-favorable location in the country.
Why not pick 3.9 and assume that everybody gets as much as Fairbanks, Alaska?
Because the vast majority of the US gets in the range of 4.2 - 4.5? I could have used 4.5, but that would only move the total cost down by about $4,000. Still, that is the average. An off-grid system needs to be designed for the low on that chart, or there will be times of year you have little or no power.
Yes, and the sentence you quoted specifically said the $98,000 figure was using Tesla's batteries.
Ok, so assuming that you really do need ~60kwh and you must use Tesla's expensive batteries rather than the $8k package, that's still 21 + 3 * 8 batteries = $45k for a house in California. What is the other $53k spent on? Postage?
I didn't look into where the $98,000 was supposed to be located. I assumed they took the least-favorable location in the country.
In California. It's right there in my first post.
Maybe they assumed that the average American lives in Alaska and use their air conditioning 24/7.
Comments
Look at the link you posted. The recommended battery pack for that system is 62kWh (1284Ah * 48VDC). That is the equivalent of 6 10kWh Powerwall batteries.
Furthermore, the 10kWh Powerwall is not for solar or other daily applications; it's for backup.[1] A PV system needs to use the 7kWh batteries, thus requiring 9 for this system. That is $27,000 in batteries.
Now, on to the panels. The sizing of the system you posted indicates it assumes 5 Sun hours per day. Most of the US gets less than that; from the map on the site it looks like 4.3 is a good average for the US. Next, as the site clearly says when you run their off-grid calculator, you need to discount the Sun hours if you plan on using the system in the winter; they recommend knocking 1.5 off your yearly average. That drops most of the US to 2.8. That means the median house would need twice the number of solar panels in that set to cover all times of year.
Combined with the actual cost of Powerwall batteries, we are at $67,344. If you want to use the Pacific Northwest as your baseline (which someone opposed to solar would try to do) you approach the $98,000 for an off-grid system.
[1] http://www.teslamotors.com/powerwall
Oh look. It's $8k. So the total price is $28k.
62 kwh is over two full day's worth of electricity usage for the average US home. I actually think that's probably quite a bit more than you need. Two of Elon's batteries is 20kwh, which is about 2/3 of an average day's usage - enough to last most people the night, right?
$98k was in California right? According to this, Los Angeles gets 5.62. Manhattan gets 4.57.
http://www.bigfrogmountain.com/SunHoursPerDay.html
Why not pick 3.9 and assume that everybody gets as much as Fairbanks, Alaska?
Yes, and the sentence you quoted specifically said the $98,000 figure was using Tesla's batteries.
Wrong. An off-grid PV system requires a buffer to supply power during days with little to no sun. Two days is about right for most of the country; in some places I would size it larger because they are prone to multiple days of overcast conditions at certain times of year.
Furthermore, you completely ignored that I stated, supported by the link I provided to the Tesla page, that you are not supposed to use the 10kWh batteries for daily drain applications.
I didn't look into where the $98,000 was supposed to be located. I assumed they took the least-favorable location in the country.
Because the vast majority of the US gets in the range of 4.2 - 4.5? I could have used 4.5, but that would only move the total cost down by about $4,000. Still, that is the average. An off-grid system needs to be designed for the low on that chart, or there will be times of year you have little or no power.
Ok, so assuming that you really do need ~60kwh and you must use Tesla's expensive batteries rather than the $8k package, that's still 21 + 3 * 8 batteries = $45k for a house in California. What is the other $53k spent on? Postage?
In California. It's right there in my first post.
Maybe they assumed that the average American lives in Alaska and use their air conditioning 24/7.