Tesla to blanket the US with supercharging stations in 2 years

[AustinChief]

Originally Posted by 'Hamas' Jenkins

How efficient is the average panel right now?

That's hard to say. It can vary by A LOT from panel to panel. But 20% is a good guess for the very very very best shiny new commercial grade panels. And we are talking super high end crazy expensive stuff to get to 20%. Your average home panel is lucky to hit 16%.

['Hamas' Jenkins]

Originally Posted by AustinChief

That's hard to say. It can vary by A LOT from panel to panel. But 20% is a good guess for the very very very best shiny new commercial grade panels. And we are talking super high end crazy expensive stuff to get to 20%. Your average home panel is lucky to hit 16%.

This suggests the kind of exponential growth akin to Moore's Law:

http://www.economist.com/blogs/graph...daily-chart-19

If I understand you correctly, you're saying that there is a theoretical limit to the efficiency of solar cells.

Now, if they are 20% efficient, does that mean that they are absorbing 20% of the incandescent energy from the sun? If so, how large of a panel would I need for a watt of energy?

[AustinChief]

Originally Posted by 'Hamas' Jenkins

This suggests the kind of exponential growth akin to Moore's Law:

http://www.economist.com/blogs/graph...daily-chart-19

If I understand you correctly, you're saying that there is a theoretical limit to the efficiency of solar cells.

Now, if they are 20% efficient, does that mean that they are absorbing 20% of the incandescent energy from the sun? If so, how large of a panel would I need for a watt of energy?

Ahh Swanson's law, yes, I see no reason it won't remain true since it deals only in cost and not the tech aspect itself. I am not even looking at that side of things. Even if panels were super cheap they just don't provide much energy for the amount of space required and people don't consider that they have limited lifespans and other maintenance costs... but let's ignore that for now and focus on the tech.

The simple answer is that for 1 KILOWATT of energy per day(you can convert to watt if you want) you need 1 square meter of panel. Average solar energy for most cities is around 5KW per square meter per day. So at 20% efficiency you take 5 X .20 and get 1.

Now here is where it get's interesting.. let's give Teslas to the average two car family and add up their TOTAL HOUSEHOLD electrical energy usage per day. It comes out to around 60KWh per day. So you end up with 60 square meters or around 646 sq ft of solar panels to get to break even.

Learning the realities of solar panels is kinda depressing actually.

['Hamas' Jenkins]

Originally Posted by AustinChief

Ahh Swanson's law, yes, I see no reason it won't remain true since it deals only in cost and not the tech aspect itself. I am not even looking at that side of things. Even if panels were super cheap they just don't provide much energy for the amount of space required and people don't consider that they have limited lifespans and other maintenance costs... but let's ignore that for now and focus on the tech.

The simple answer is that for 1 KILOWATT of energy per day(you can convert to watt if you want) you need 1 square meter of panel. Average solar energy for most cities is around 5KW per square meter per day. So at 20% efficiency you take 5 X .20 and get 1.

Now here is where it get's interesting.. let's give Teslas to the average two car family and add up their TOTAL HOUSEHOLD electrical energy usage per day. It comes out to around 60KWh per day. So you end up with 60 square meters or around 646 sq ft of solar panels to get to break even.

Learning the realities of solar panels is kinda depressing actually.

30x20 of solar panels isn't that depressing. That would fit just fine on most roofs, wouldn't it?

[AustinChief]

Originally Posted by 'Hamas' Jenkins

30x20 of solar panels isn't that depressing. That would fit just fine on most roofs, wouldn't it?

Given that there is no shade and the roof is entirely slanted toward the sun... maybe. Don't get me wrong, I'm not against solar energy... but everything we are discussing doesn't take into account the install costs, the maintenance, the lifespan, etc etc

Originally Posted by mesmith31

Now here you have a project that understands the scope of coverage required to get the kind of power needed. It's completely impractical on many levels but it shows the massive square footage you are talking about when you look at our power requirements.

The biggest issue is a simple one... we just waste too damn much energy. That isn't likely to change much. Which is why I am a huge proponent of funding fusion research. As "impractical" as it sounds, it is actually one of the most realistic measures we can take towards safe, clean renewable energy that would exceed demand such that it would drive down costs and could theoretically bring a boatload of manufacturing back to the US. As we move more and more toward automation, energy and transport costs not labor will be the deciding factor on where a factory gets built.

['Hamas' Jenkins]

Originally Posted by AustinChief

Given that there is no shade and the roof is entirely slanted toward the sun... maybe. Don't get me wrong, I'm not against solar energy... but everything we are discussing doesn't take into account the install costs, the maintenance, the lifespan, etc etc



Now here you have a project that understands the scope of coverage required to get the kind of power needed. It's completely impractical on many levels but it shows the massive square footage you are talking about when you look at our power requirements.

The biggest issue is a simple one... we just waste too damn much energy. That isn't likely to change much. Which is why I am a huge proponent of funding fusion research. As "impractical" as it sounds, it is actually one of the most realistic measures we can take towards safe, clean renewable energy that would exceed demand such that it would drive down costs and could theoretically bring a boatload of manufacturing back to the US. As we move more and more toward automation, energy and transport costs not labor will be the deciding factor on where a factory gets built.

What do you think it would take to initiate a self-sustaining and safe fusion reaction?

[AustinChief]

Originally Posted by 'Hamas' Jenkins

What do you think it would take to initiate a self-sustaining and safe fusion reaction?

The safe part is the easiest part. Unlike fission, a fusion reactor that has a catastrophic failure simple stops. The only "unsafe" part of it is the irradiation of any casing/shielding materials which produce a minimal amount of waste. The "Holy Grail" is to get to aneutronic fusion which eliminates that by creating a reaction whose byproduct can be converted directly to electrical energy. Think of it in terms of creating a mini sun to power solar cells. That isn't accurate but it works well enough as an analogy.

The self-sustaining part is where we have problems. The term for this is "ignition." You have two basic approaches to achieve this. I can go into details if anyone cares but let's just say the US facility working on this uses lasers and the Europeans use magnets. (Wow, that is so oversimplified it sounds stupid) At one point we were ahead of the Europeans on this but massive cutbacks in funding (thanks to both Obama and Congress) have let the Europeans jump ahead. It actually doesn't matter who "wins" the race in this both approaches have significantly advanced the science in recent years.

Ok, let's focus on the Euro project, ITER, since they are currently in the lead. (could change at any point though and I still think NIF has a more solid approach) The Euros aren't messing around. They are building an experimental reactor now and expect it to be operational by the 2030s. IF it works, they expect to produce 10 times the energy that is put into the reaction.

I can go through a litany of engineering issues that both projects are facing but the real issue is funding. We know the science works it's now down to engineering issues which can always be solved with time and money. The problem is that the scale of time and money we are talking about is pretty damn huge, but the payoff is well worth it in my mind.

[SPATCH]

Originally Posted by AustinChief

Given that there is no shade and the roof is entirely slanted toward the sun... maybe. Don't get me wrong, I'm not against solar energy... but everything we are discussing doesn't take into account the install costs, the maintenance, the lifespan, etc etc

install costs, maintenance, etc. don't scare me as much as knowingly continuing to increase our dependency on an energy source that is not renewable.

There are challenges facing green technology.. but that's exciting. I hope that advancing renewable energy will be one of the great feats that we accomplish as humans of the early 21st century.

[AustinChief]

Originally Posted by the_spatula

install costs, maintenance, etc. don't scare me as much as knowingly continuing to increase our dependency on an energy source that is not renewable.

There are challenges facing green technology.. but that's exciting. I hope that advancing renewable energy will be one of the great feats that we accomplish as humans of the early 21st century.

I agree I just look at all the limitations and think we currently have a "middle of the road" approach to things. We are looking past the short term of fossil fuels but are jumping the gun and wasting a ton of money on "solutions" that are half baked and simply CAN'T EVER truly meet our long term needs. Again, this is why I'm a "fusion guy."