New Electrical Panel Installed - Siemens Solar Ready

**sensij** · 11-02-2014, 12:21 AM

Originally posted by Sunnyvalejohn

"Title 24 - On July 1, 2014, California implemented significant and far reaching building code revisions known collectively as Title 24. As a whole, these code changes are intended to standardize energy efficient design and construction methods for both residential and commercial buildings. Additionally, they respond to the AB32 legislation that requires all new residential construction in California be Zero Net Energy by 2020. Once new requirement is that new homes be made "Solar Ready". While the new standard does not mandate solar panel installation at the time of construction, it does define new solar provisioning requirements designed to make future solar electric installations easier and more affordable for home owners. As part of the solar ready requirements, Title 24 also defines new guidelines for the main electrical service panel used in new residential construction in subdivisions of 10 or more homes. Under the new code, the main electrical panel must have a minimum busbar rating of 200 amps. Additionally, all service entry panels are required to have 2 reserved spaces on the load-side to allow for installation of a double pole circuit breaker for future solar electric installation. These reserved spaces are required to be on the opposite (load) end from the main circuit breaker on the busbar and permanently marked as "For Future Solar Electric". To meet the new requirements that pertain to the main electrical service panel used in the construction of new residences, as well as support increasing market demands for products that support solar energy installations, Siemens offers a full portfolio of meter-load center combination devices."

Stuff like this makes me so sad to be a Californian.

**CA_Tom** · 11-02-2014, 12:42 AM

Originally posted by sensij

Stuff like this makes me so sad to be a Californian.

Why?

Seems to me like a law that costs nothing for developers to comply with. And provides a benefit to the homeowner.

(OK... it costs the developer $1 for a label to put on the panel saying 'reserved for solar' on the two slots. I think they actually can use that as a selling point though.)

**sensij** · 11-02-2014, 01:14 AM

Originally posted by CA_Tom

Why?

Seems to me like a law that costs nothing for developers to comply with. And provides a benefit to the homeowner.

(OK... it costs the developer $1 for a label to put on the panel saying 'reserved for solar' on the two slots. I think they actually can use that as a selling point though.)

Installing a PV system will not make sense for everyone, so why require every house being built in the development to encourage it? If the requirements are no big deal and cost nothing, why legislate it at all? At least with regard to solar, let people make their own decisions.

Here's the full text, section 110.10 is related to solar.

**CA_Tom** · 11-02-2014, 03:04 AM

Originally posted by sensij

Installing a PV system will not make sense for everyone, so why require every house being built in the development to encourage it? If the requirements are no big deal and cost nothing, why legislate it at all? At least with regard to solar, let people make their own decisions.

How much more do you think it costs for an end-feed panel and to set aside the last two spots on that panel as reserved?

Now if the requirement wasn't in place, would a developer reserve those two spots? Or use an end feed panel?
Would the electrician just start at one end and work his way toward the other? (and it'd be a 50-50 chance that he'd start at the far end vs. the end nearest the feed?)

This requirement (end feed, reserve 2 breaker slots) is basically zero additional cost to a developer.

The electrician has to skip two slots if he starts at that end - so figure 24" more wire (extra 2" on each of ~12 breakers as they shift up/down 2 inches) Is there any real cost to the developer for that? No. Maybe the electrician has a few ounces less of scrap copper from trimming the wires - not enough that he'll charge more.

End feed breaker panel instead of a center-feed - is that really an extra cost? Probably not. (feel free to show me otherwise, but it seems end-feed is pretty cheap)

200A instead of 100A panel - is that really an extra cost? *maybe* - but I think most panels going into new houses were 200A anyhow already. (A cheap 200A panel is $54 at HD vs. $53 for 100A (with fewer spaces) - probably 200A sells more so get some economy of scale so it's same price or maybe even cheaper depending on what configuration you are looking for.)

Label for those two spots? yep - here's an extra $1 the developer has to spend.

Now - lets be generous - and say the developer actually has to spend $5 extra and that $5 extra of course gets passed along to the home purchaser in increased cost for their home. Is that a public good that every buyer paid that extra $5? For the 1/100 people who do install solar it was a *great* thing. Instead of spending $3k for a new panel they're ready to go. So that one person is saving $3k and the other 99 are spending $5 each. So the net benefit to the whole group is $2500. And if you look at it that maybe now instead of 10 out of 1000 people install solar now it makes economic sense for 12 of the 1000 to do it (because it's $3k less expensive than it would be otherwise) - that's also a net benefit to the whole group.

As for why legislate it?
Because generally people aren't going to be thinking about whether 10 years from now they can install solar on that home - they have 50 other things they need to pay attention to - like what pattern for the kitchen floor, what tile for the bathroom, which appliances, etc. etc. etc.

**sensij** · 11-02-2014, 03:51 AM

If you are calculating net benefit, please don't neglect the costs associated with the salary of the lawmakers, lobbyists, clerks, etc who spent time figuring out that we would be better off with this law than without. If you want to maintain that some portion of that is sunk cost, there should at least be some kind of opportunity cost... unless you want to say that making homes solar ready is the most pressing thing our representatives should be working on, because they have solved all of the more important problems.

How is it saving $3000 per install if all that needed to be done was to move the breakers on the end to another slot so it could be end fed? As you say, most panels going into new homes are 200 A anyway. Center-fed panels would be expensive to replace, but what subset of all new residential panel installs are those?

How is requiring 200 A panels promoting energy efficiency? It would seem to me that a person with 100 A service might be more motivated to be efficient if it means they can avoid an expensive panel upgrade.

**Bikerscum** · 11-02-2014, 09:19 AM

The small (relatively) town I live in in the SF Bay area is about to be the only city in the area to get gigabit (1000 MBPS) high speed internet service. Only about 50 cities in the whole country have it. Why us? Because the city leaders, back in 1999 mandated that all new construction permits residential and commercial would include an underground fiber optic conduit. The internet and nationwide unlimited home phone service will be $39.99/mo.

That was 15 years ago, and I guarantee people were bitching then about having to pay for something they would never use.

**sensij** · 11-02-2014, 11:03 AM

Originally posted by Bikerscum

The small (relatively) town I live in in the SF Bay area is about to be the only city in the area to get gigabit (1000 MBPS) high speed internet service. Only about 50 cities in the whole country have it. Why us? Because the city leaders, back in 1999 mandated that all new construction permits residential and commercial would include an underground fiber optic conduit. The internet and nationwide unlimited home phone service will be $39.99/mo.

That was 15 years ago, and I guarantee people were bitching then about having to pay for something they would never use.

That would be a fair comparison if people could freely choose to have fiber installed relatively inexpensively whenever they want, like they can with residential PV systems. You are talking about an actual infrastructure improvement, with significant economies of scale, and that is a great place for legislation to be involved. I'm not sure how they would have been able to justify building the fiber trunks if they didn't also require the houses to be hooked up.

**russ** · 11-02-2014, 11:34 AM

Originally posted by sensij

You are talking about an actual infrastructure improvement, with significant economies of scale, and that is a great place for legislation to be involved.

That is one great advantage the US has had over the years - infrastructure could be planned many years in advance - a pre-investment.

The down side of it is you end up with legacy systems that make changing to newer technology expensive and unattractive.

**CA_Tom** · 11-02-2014, 12:46 PM

Originally posted by sensij

How is requiring 200 A panels promoting energy efficiency? It would seem to me that a person with 100 A service might be more motivated to be efficient if it means they can avoid an expensive panel upgrade.

When you're required to upgrade from 100A to 200A isn't really related to how efficient you are. It's more related to the calculated load - so if you want to add a new circuit for something like a electric car you should do the calculations to see if you need to upgrade.

From a practical point - On a 100A panel you could use something like 13000 kwh each month. Sure that's absurd - I'd guess most households use like 10% of that. So 100A or 200A doesn't really matter for the homeowner - either limit is much higher than the homeowner actually uses. Even when growing up with 60A service the size of the service wasn't ever a consideration that drove being more energy efficient.

If you are calculating net benefit, please don't neglect the costs associated with the salary of the lawmakers, lobbyists, clerks, etc who spent time figuring out that we would be better off with this law than without. If you want to maintain that some portion of that is sunk cost, there should at least be some kind of opportunity cost...

That would all be sunk cost.
Even if the law wasn't passed all that time and costs would have been spent.

As for opportunity cost - I'd argue the flip side of that. Them spending time on this - which has a real benefit and no downside - is a much better thing than if they're spending time on <*insert items that you think is wasteful spending here*>

**bcroe** · 11-02-2014, 11:38 PM

Originally posted by CA_Tom

This requirement (end feed, reserve 2 breaker slots) is
basically zero additional cost to a developer.

The electrician has to skip two slots if he starts at that end - so figure 24" more wire (extra 2" on each of ~12 breakers as they shift up/down 2 inches) Is there any real cost to the developer for that? No.

200A instead of 100A panel - is that really an extra cost? *maybe* - but I think most panels going into new houses were 200A anyhow already. (A cheap 200A panel is $54 at HD vs. $53 for 100A (with fewer spaces) - probably 200A sells more so get some economy of scale so it's same price or maybe even cheaper depending on what configuration you are looking for.)

The 2 reserved PV slots can always be populated with regular circuits later. The main cost
for a 200A box will be the larger copper conductors & support parts feeding it. Bruce Roe

New Electrical Panel Installed - Siemens Solar Ready

New Electrical Panel Installed - Siemens Solar Ready

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