7 ms·
This is much more groundbreaking than it may appear. The innovation is entirely in the price. At $3500, you can put in two and be entirely off grid. Solar pa
by marze 11y ago
This is much more groundbreaking than it may appear. The innovation is entirely in the price.
At $3500, you can put in two and be entirely off grid. Solar panels are cheap enough you only need batteries to last one night, as you can size the array to operate your loads even on cloudy days.
- kondro 11y ago2 is not enough. 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time. 4kW inverters seem to be around the $1000 mark… but they don't seem to increase linearly (10kW inverter $4000 for example). Of course you could go totally off-grid, but the cost isn't going to be just $7k… it's likely to be at least $15-20k by the time you get everything you need and installed. At that price, you could've bought a larger capacity deep-cycle storage solution already readily available on the market with batteries that will last 20+ years.
- marze 11y agoObviously there is a lot more than just the batteries. In solar systems, $7k is not a big amount compared to all the other expenses. I'm assuming you'd minimize your loads, it is silly to size your solar system for a business-as-usual set of loads.
- kondro 11y agoYou definitely could, but that will increase costs even further. You're potentially replacing all your lighting, climate-control, water heating, cleaning (dishes/clothes), cooking & fridge/s to be more energy efficient also. Actual power storage is a reasonably small cost (probably < 20%) in even the solar, power equipment (inverter, switches, controllers, etc), power-storage equation anyway if you want to go completely off-grid. So why does this product make anyone more likely to switch than the existing options?
- marze 11y agoGoing off grid isn't something one does lightly.
- kondro 11y agoWhich was my point :). You seemed to be suggesting you could just buy 2x $3500 batteries and go completely off the grid.
- marze 11y agoObviously you can't go off grid without a solar system, what would charge the batteries? To quote from the original post: "Solar panels are cheap enough you only need batteries to last one night, as you can size the array to operate your loads even on cloudy days."
- toomuchtodo 11y ago> At that price, you could've bought a larger capacity deep-cycle storage solution already readily available on the market with batteries that will last 20+ years. Citation? Deep cycle lead acid batteries have a maximum life expectancy of 5-8 years, even if aggressively managed.
- kondro 11y agoIron Edison talks about their Ni-Fe batteries lasting 25+ years. http://ironedison.com/iron-edison-usa-series-nickel-iron-nife-battery http://ironedison.com/iron-edison-usa-series-nickel-iron-nif...
- toomuchtodo 11y agoBut do they actually warranty them for that long? I could find no mention of a warranty on their site.
- kondro 11y agoThey provide a 10 year warranty on their Ni-Fe batteries… but their spec sheets allow for a much longer lifespan: https://ironedison.com/renewable-energy-batteries https://ironedison.com/renewable-energy-batteries
- marze 11y agoPrice reference? Looks like they are 2x Tesla's price.
- Johnythree 11y agoMy 2200ah Lead Acid bank is still healthy after almost 20 years. Just did some load tests yesterday.
- toomuchtodo 11y agoAre they flooded? Do you have to maintain them? I assume you keep them in a battery box that's ventilated? Tesla's product requires none of that to be done.
- Johnythree 11y agoThe key to successful Solar Living is an understanding of energy efficiency. Suggesting running an electric oven on solar is crazy talk.
- Dylan16807 11y agoSo if your main priority is carbon what do you do, use a wood oven?
- eru 11y agoUse the heat directly, like in a concave mirror?
- kragen 11y agoMaybe a solar oven? Unlike Li-ion batteries and solar cells, you can make a solar oven without mass production and using materials fabrication technologies available 2000 years ago. (You can make it cheaper if you use modern mirrors instead of polished bronze.) Typical solar cells are 16% efficient; your pre-medieval-materials solar oven will be about 50% efficient.
- sswaner 11y agoHave you ever tried to bake in a solar oven? In anything less than ideal solar conditions baking either fails completely or takes a long time.
- kragen 11y agoI admit that I haven’t! However, I think you’re talking about baking in a crappy solar oven, not baking in a solar oven in general. For example, http://www.solare-bruecke.org/infoartikel/Papers_%20from_SCI_Conference_2006/22_wolfgang_scheffler.pdf http://www.solare-bruecke.org/infoartikel/Papers_%20from_SCI... describes a 3.4m² kilowatt prototype solar oven successfully used to cremate chunks of goat meat at temperatures of 800° to 900° in under an hour. Larger solar ovens (usually known as “solar furnaces”) can reach 4000°, adequate not just for cooking or even cremation but also for firing terra-cotta, blowing glass, calcining lime, firing earthenware, making glass, firing porcelain, calcining portland cement, making borosilicate glass, casting aluminum, melting porcelain, purifying metals by zone melting, casting iron, smelting iron, casting steel, melting lime refractory, making quartz glass, casting basalt, boiling aluminum, vaporizing steel, vaporizing quartz, vaporizing lime refractory, melting tungsten, and sublimating graphite. Although people have been doing most of these with solar ovens for a while, especially the famous solar furnace at Odeillo, you can’t do all of these with Iron Age materials; apparently if you want to do anything useful with melted tungsten, you have to use Ta₄HfC₅ or similar. Of course none of this works when it’s cloudy or dark, although molten-salt heat storage might be a usable solution to that even at a household scale.
- roel_v 11y ago" 4kW seems to be the maximum potential drain from the battery. That wouldn't power an oven… let alone anything else at the same time." 4kW is enough to power an entire home continuously, without thinking about energy use, even a large one with a home office with several people working in it + washing machine + oven + electrical stove at the same time. I have the data to prove it, too - 10 second interval power consumption logs for the last 4 months for my house/office, and I never had a load of more than 3.5kW. To be fair, this is all with modern, top of the line appliances, so yes that 199$ no-brand Chinese oven will probably draw a lot more power, but still. Worst case, you'd need a second 'peak power' supply, which could provide e.g. 6 or 8 kw for 10 mins max, maybe using some sort of XXL capacitor. I don't know about the EE side of this, or whether such a thing exists already, just saying - 4kW is perfectly feasible and even heavy users would maybe need just a little bit more. (of course this also assumes you have a better quality house than the standard American cardboard 'house' in which you need A/C running 24/7 just to not die in summer).
- brc 11y agoMy air conditioner is 12 kW. No chance.
- roel_v 11y agoIf your air conditioner actually draws 52 amps at 230 volts (or 110 @ 110 if you're in the US), you must be air conditioning a gym hall with a black, tin roof somewhere in a desert. But you're probably not, and that was my whole point - my stove top is rated at 10kW, too, yet even when using alongside all other appliances in my house I have never gone above 4kW actual use. Actual need != summing all the nominal maximum rated loads of all appliances. In other words, it's not because your AC is rated 12kW, that you'd need 3 of these battery packs just for the AC. You might need 2, or maybe 3, I'm not saying that 2 (or 4) kW is enough always, everywhere for everybody - but there is no 'normal' (middle to upper middle class) home anywhere that would need 5 or 10 of these units, as is suggested at various places in this thread.
- brc 11y ago