Path: ...!weretis.net!feeder9.news.weretis.net!news.quux.org!eternal-september.org!feeder3.eternal-september.org!news.eternal-september.org!eternal-september.org!.POSTED!not-for-mail
From: Bill Sloman <bill.sloman@ieee.org>
Newsgroups: sci.electronics.design
Subject: Re: Grand Apagon - Electricity (not) in Spain
Date: Wed, 30 Apr 2025 22:37:39 +1000
Organization: A noiseless patient Spider
Lines: 38
Message-ID: <vut5ir$9m4f$1@dont-email.me>
References: <vuqgef$1of93$1@dont-email.me>
 <mqp11khbm5eoulgl4i7l1ncmm73irtnk5q@4ax.com>
 <6810ef6a$2$2786$882e4bbb@reader.netnews.com>
 <qft11klssklbte9o8mu13o9m8jla77649r@4ax.com> <vusi3d$3lvur$5@dont-email.me>
 <vusuof$3ntuc$2@dont-email.me>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Injection-Date: Wed, 30 Apr 2025 14:37:48 +0200 (CEST)
Injection-Info: dont-email.me; posting-host="1beaba84e4b2ae4d867f48feacce2a95";
	logging-data="317583"; mail-complaints-to="abuse@eternal-september.org";	posting-account="U2FsdGVkX18bMBYjOWQaXNxe166YAbqTVK14giwgW1E="
User-Agent: Mozilla Thunderbird
Cancel-Lock: sha1:AA9g6S/p9yCbBVT0k+ohDFEtIFE=
X-Antivirus: Norton (VPS 250430-2, 30/4/2025), Outbound message
In-Reply-To: <vusuof$3ntuc$2@dont-email.me>
Content-Language: en-US
X-Antivirus-Status: Clean
Bytes: 3315

On 30/04/2025 8:41 pm, Jeff Layman wrote:
> On 30/04/2025 08:05, Bill Sloman wrote:
> 
>> About 40% of new roof-top solar power installations in Australia include
>> a Tesla Powerwall (or something similar) to keep the lights on at night.
>>
>> It adds appreciably to the capital cost, but pays for itself in a couple
>> of years. Australia's feed-in tariffs aren't generous.
> 
> Over here in the UK a 13.5kWh Tesla 3 powerwall will cost around £10k 
> (includes installation). This (USA) site suggests a payback time of 14 
> years 
> <https://www.solarreviews.com/blog/is-the-tesla-powerwall-the-best-solar-battery-available#is-the-tesla-powerwall-worth-the-price?>.
> 
> This Australian site 
> <https://cleannrg.com.au/the-real-cost-of-teslas-powerwall-battery-storage/> seems to suggest that a powerwall save A$3000 a year, but the initial cost is A$20000. Doesn't that make the payback time 6 - 7 years rather than just a couple?

Strictly speaking it's the pay-off time for the battery on it's own 
which is the issue. Roof-top solar is a popular investment, but on your 
figures at takes about three years to pay for itself.

Adding the battery is a separate investment which cuts your power bills 
a lot more, and the time to pay off just the battery is about five years 
- on those numbers. You pay off your solar cells and their inverter 
system quite a lot faster too. Without the battery it takes about three 
years, with the battery an additional 20 months.

I suppose it also depends on the battery you use. The Chinese BYD Blade 
battery seems to be better than it's Tesla equivalent. Whether a BYD 
powerwall could be cheaper than it's Tesla equivalent is anybody's guess.

https://en.wikipedia.org/wiki/BYD_Blade_battery

I was just quoting some local newspaper articles. Adding the battery to 
your roof-top solar does seem to be surprisingly popular here.

-- 
Bill Sloman, Sydney