Solar Expansion & NEC Code 690.64(B)(2) Issues

It's been a while since my last post. Enjoying the new house immensely. We decided this past year to increase our solar system size on the roof in preparation for an electric car. I thought it would be beneficial to share our experience.

The previous system is a 36 panel (5.8kW) with 6000 Watt Sunny Boy inverter.

The new system is a 10 panel (2.2 kW) with 4000 Watt Solectria inverter. It has some room to grow to fully use up the 4000W inverter.

(I was quite amazed at how the panel costs have fallen to half of what they were in 2006! All of the new system was purchased from an outfit called Solar Depot in Petaluma. Although California's incentives are almost nothing now, the Federal 35% tax credit incentive is sweet to bring costs down even further).

When we connected the two systems to the 200A panel that we have, I was made aware of NEC code 690.64(B)(2) which is a fire code. The panel must have a main breaker that can carry the sum of both inverts and meet this NEC code. The code as it pertains to a residential installation says:

"For a dwelling unit, the sum of the ampere ratings of the overcurrent devices shall not exceed 120 percent of the rating of the busbar or conductor."

Here were our calculations of the circuit break requirements for our two inverters:

6000W/240V = 25, then 25 x 1.25 = 31.25A so a 35A breaker is used.

4000W/240V = 16.7, then 16.7 x 1.25 = 20.8A so a 25A breaker is used.

The current panel is 200A so 120% x 200A = 240A. If we just connected both solar systems into the panel with 35A + 25A breakers = 60A, then 200A + 60A exceeds the 240A maximum.

We struggled with issue for many months trying to find a solution that avoided us having to scrap the new 200A panel we put in when we built our house, which would require breaking stucco and rewiring the whole thing, or adding a new panel and again costing a lot to install it etc.

We were unable to get answers from the solar reseller, our utility PG&E, the City of San Mateo and various electrical distributors for the panels. It appears that runing up against this code issue is rare, but I suspect it will become increasingly problematic for those of you who put up large solar systems.

The solar reseller said "do a line side tap" to avoid the panel bus - how the heck do you safely splice together a solar system wire with the wire on the meter side of the panel and meet PG&E requirements? We looked into special splicing lugs, but none could be mounted safely within the PG&E side of the meter. The PG&E inspector had never seen or heard of anyone doing that and was not thrilled by the lug solution sitting on their side of the panel.

The City of San Mateo had no idea - they had not run into this before and had insufficient training.

The panel distributors could not recommend any parts to do a line side tap, no one had asked for this before at the couple of shops I called.

So I turned to an expert on this subject - John Wiles at University of New Mexico, who proved quite helpful. John published a series of papers that ultimately helped us identify a solution. Here is one called Supply Side PV Utility Connections and another called Making the Utility Connection.

What we determined was that, although not ideal, if we could downrate our main house circuit breaker, we could meet the 120% requirement without having to install a new panel and break stucco.

We did a load analysis of the house to show that the house only needed a 175A main breaker. So by switching out the 200A main breaker to 175A, the load would be:

175A (house) + 35A (solar 1)+ 25A (solar 2) = 235A which is < 240A and meets the NEC code.

Our electrician used a simple load analysis spreadsheet available from the Inspection Bureau (IBI) here to do the calculations, going room by room and listing appliances etc. Our house load ended up being about 150A.

We then got the City to sign off, which they did and were very appreciative of my assistance in helping them understand this important safety issue. PG&E signed off too since we did not have to do anything on their side of the meter.

My advice for any of you building a new home: plan in advance, if you expect to put up a large solar system, be sure to provision for a large panel size - my recommendation being 400A - so that you can easily connect the solar system to the panel and have room to grow, rather than deal with the complexities of a line side tap or switching out your panel in the future.

Net Meter vs Time of Use

We received a letter from PG&E our local utility letting us know that they had re-opened Time of Use "E7" rate metering to electric customers who installed solar this year. They are allowing 5,000 new customers as part of a negotiation they reached with the California Public Utility Commission. My bet is that this was mandated by PUC as part of their monopoly conditions otherwise it has to be a money loser for PG&E and why would they do that?

I checked into the rates, which pay around $0.35/kW and up per minute for peak (noon to 6pm Mon-Fri) and $0.09/kW for off peak and compared this to our current Net Metering rates which simply pay a flat fee no matter what time of day. It turns out that most of our solar is generated between noon and 6pm each day, at least 60%. That means we will be paid for that generation at the higher $0.35 or more rate. We also don't consume much during that time with not much air conditioning or appliance use. I was told by our solar supplier that if you consume <25% of your power usage during peak, it makes sense to go to E7 TOU metering.

So we went ahead and did it. PG&E swapped out the meter at no charge and I've been keeping an eye on the readings. I think we will significantly improve our payback on the equipment as a result. Maybe by 1-2 years.

Keep in mind that they are closing this special "deal" rate when they hit 5,000 customers and you can only apply if your system was commissioned in 2007. The number is 800-468-4743. You are also locked in to that rate for a year so be careful to calculate accurately if it makes sense for you to switch.

It's been nice to see our system gradually generating more power each day as the days get longer. Yesterday we hit 36 KwH with our 5.8 kW system. We're selling back net net these days!

Landscaping

It's been a while since our last post. We've been enjoying the new house, getting settled in and all. The buzz of people around working on things here has dropped considerably and the project is quickly coming to an end, although we keep saying that and there seem to be new things to do all the time on the landscaping front.

The past couple of months have seen the construction of our deck off the back of the family room, two new fences on each side of the house to create a little more privacy and the follow up on a punch list that is almost down to nothing now. We also upgraded our solar system to add another 1kw (now 6kw) as we were finding our electricity usage a little higher than originally predicted.

The vast majority of work is done on the hardscape. Our previous landscape designer abandoned us recently due to too many commitments but fortunately we connected with Nancy Higgins, a really great planting consultant, who walked through and guided us in 3 hours on our entire plantings list. After much shopping around, we ordered everything from a wholesaler in Stockton, Delta Tree. Normally they do not sell to the general public but we were able to get wholesale pricing through our relationship with our builder Structural FX - half the price of our local nurseries. The plants should arrive in a couple of weeks and that will conclude the landscaping part of our build.

Kitchen

Here is the completed kitchen. The cabinets were Thomasville cottage in natural cherry (available at your local Home Depot, who have great free design services). The key in making them look custom is to add "skins" to the outside to finish them nicely on sides facing you. We also added light rail along the bottom to hide the florescent lights under the cabinets and a modified crown moulding along the top, making the band a little thicker be adding in a section of "skin" between the crown, thin scribe moulding to hide the gap between cabinet and wall and light rail. The same pattern was pulled all the way around the kitchen to give it a nice consistent look. All this courtesy of some clever designing by Structural FX on site.

The counters are Tan Brown pre-fab granite. We ordered these from EMG out of Concord, CA mainly because they were the only ones with the 52" x 9 foot pre fab island. I have to say, buying pre fab is a huge savings if you can find stone you like, at least 1/3 the price of a custom stone job. EMG did all the slab cuts and cut out the sinks, faucets and built one side of the island bullnose on site. The tile you see along the back splash and under the vent is a copper tile. It's real copper in squares covers that are fitted over a ceramic base. It takes a special epoxy grout and sealer combo to finish it and once that is applied, there is no further maintenance and the copper should not change color.

The appliances - Sub Zero 601R refrigerator with stainless steel door, Sub Zero 601F Freezer overlaid in cherry to hide the unit near our mini office area, Sub Zero 424S under counter wine cooler which has a neat two zone control for whites and red, viking 36" range top with griddle already used several times now to make pancakes, Thermador microwave/convection combo double oven, Miele Incognito dishwasher, Vent a Hood 42" chimney vent, KitchenAid trash compactor and an additional GE microwave in the island near the refrigerator to heat up leftovers.

A few observations: the Sub Zero 424S is a little noisy especially at night you here it clicking on/off. The fridge and freezer are awesome with their layouts for storage inside. The Viking range kicks butt on heat and quickly cools down. The Vent a Hood magic lung is unbelievably cool - the smoke goes straight up, curls around into the side "magic lungs" and the grease gets pulverized - no cleaning, no smell at all. It's superb and the sales guy was absolutely right to say this is hands down the best in the industry and puts our previous high end Wold vent to shame. The Miele dishasher is so quiet you really have to put your ear next to it and listen carefully to hear that it started up. The top utensil tray takes a little getting used to as you cannot just plunk the utensils down, you have to organize them into little holders all stacked one after the other. Once you get used to it, it's ok and it makes emptying the dishwasher a lot easier. The unit does a great job at cleaning. No rinsing needed before putting the dirty dishes in. Having the extra microwave near the fridge is really nice. We use it all the time. The Insinkerator pro SS units in the sink work great - very quickly mashing up the mess. We're glad we chose the Grohe Europlus II faucets for the main sink and island. They work very well.

Our cabinet layout is working out great so far. We arranged to have all the cutlery and zip lock storage near the fridge and dishwasher. It makes putting leftovers away and packing kids lunches really easy. The only thing we miss is having a slide out type drawer under the range top. We got used to this at our rental house kitchen and it could not be done in our new kitchen because the range top has to sit pretty deep in the cabinet. We still have two shelves under there so it's fairly easy to pull out pots and pans. The narrow cabinet that is in the indented part where we sit has become the liquor cabinet, a good spot. We have all the baking stuff on the back side of the island next to the wine cooler. Having two sinks back to back is also working out great. The main sink, a deep and huge Franke stainless, can hold a mountain of dishes. The smaller Franke stainless in the island is great for food preparation. The double can recylcing cabinet next to the trash compactor makes it very easy to recycle but it tends to fill up rather quickly as it doesn;t hold that much. I don't think there is any good solution to this but ours works well.

The bay window in the middle provides fantastic light but we ordered some faux wood shades that are on the way as we have a view straight into our neighbors master bedroom due to the set back of the house. The four Hubbardton Kakomi pendant lights throw off a lot of light and are very elegant. I hate to think what electricity they are using up. We're fortunately mitigating this with our newly commissioned solar power system up and running for two days now. It's nice to see our electric meter turning backwards during the day!

Having a big pantry is something we should have always had. Easy to see everything you have so you stop buying duplicate products every week at the grocery store and you actually use things up more efficiently. It has adjustable shelves and stores a huge amount of food, small appliances and various other sundries. Access to the attic is through our pantry with a pull down door. Not the greatest spot for the door as it bumps into a lot of things but we didn't have much choice.

Overall we're very pleased. The only complaint is that because we ordered our kitchen in advance of the framing of the windows, we had to be a little too conservative on the width of our cabinets to allow slack for the bay window. Now that the window is in, we could have had much wider glass cabinets and this is where we store our dishes. I'll forever be reminded of that now since we have to open two doors to put a dish plate into the cabinet - darn it. In retrspect we should have waited to order these two cabinets until after the window went in.

Cable Rail Staircase

A photo of the completed cable rail on our staircase. We had a metal rail custom welded and powder coated in "antique penny" color. The posts were welded to the top section and a couple of T footings were bolted to the floor so the whole thing would slide into place and could be locked down with a screw in each T footing. That made it a lot easier to assemble and lock it down.

We sourced our cable railes from Ultratec sold by the Cable Connection. We used 3/16" stainless steel cable that had a "stud" swaged on one end (machine clamped on). The stud screws into a lock fitting that you can get of various lengths to fit through the rail post width you choose. At the other end, the cable has nothing on it and you cut it to length and put a self locking fitting on that end once it is in place in the rail post. Then you tighten the lock fitting with an allen key. It's a little tricky to do, especially trying to turn a cable 90 degrees in a post. You're not supposed to do that because it's really hard but Structural FX pulled it off. It looks really nice with the Hubbardton lights we chose around it and beige berber carpet.

Slate Fireplace

Here is a photo of the completed slate surround on our fireplace. It took two shipments from Vermont Natural Stone but the second time the shipper worked out great (Old Dominion) with no damage. It was glued together with some metal anchor hooks in the back of the main column and mantel pieces to hook it into the wall. Most of the pieces facing out are natural split stone (rough surface) and then we had a few edges honed like the mantel piece which is one long 74" slab that came out of Pennsylvania. The grey middle pieces are "J-grey" slate. We used a pewter colored grout and then covered the whole thing in a high gloss wet look style sealer.

The fireplace insert is a Napoleon NZ26. It's a superb unit that draws air from outside through heating tubes and has an automatic thermostat to blow hot air into the house. I've had a hard time burning 3 small California oak logs in a 3 hour period, that's how efficient it is.

All that remains is to put a metal trim bar around the transition from the slate to the fireplace insert where you can still see the drywall a little. I also need to figure out a way to get a screen on this baby. We like to hear the crackling sound which you cannot do if you close the main door. You are supposed to operate it door closed but it's nice to hear that crackling.

We're very pleased with the way it all turned out. Thanks to the Structural FX team who did the assembly.

We're Moved in!

We're way behind on a blog post because.....we've been frantically unpacking and getting settled in. The movers arrived on Dec 22 and we got ourselves into the house, which was in great shape thanks to a hurculean effort on the part of the crews.

So lets back up and update you on what's been happening the past few days:

- Our slate arrived from Vermont Natural Stone, this time shipped by Old Dominion freight, a much better shipper than SAIA that wrecked our last batch. All arrived in order and was installed on Friday. I'll get a picture out soon enough, it looks terrific. We tried out our Napoleon fireplace during the holidays and it works just great.

- Our half bath granite vessel, automatic sink faucet from Faucet Decor and Toto washlet were all hooked up. If you have never tried a washlet before, I highly encourage it. We had to add a magazine rack in the bathroom...you have to love that heated seat and the warm air dryer.

- The cable rail was finished on the stairway. It was a challenge to get it all to connect right in a tight spot but Brian and Barney of Structural FX made it work. I have to say, it looks awesome and makes the staircase area really stand out now.

- The carpet was all installed just before we moved in. No problems and high praise for Paul Ondricek who carried out the work. He even came back on a Saturday to finish our stairway just before Christmas.

- Once we moved in, we logged a list of minor issues that needed to be addressed, pretty normal for a new house. Things like screws missing, trim pieces not quite sticking, plumbing switched around. Brian and team quickly addressed these and the list is getting down to almost nothing.

- Above and beyond the call of duty, the Structural FX team helped with a lot of other things outside the scope of their work - putting up blinds and bike hooks, helping move stuff in, cutting extra shelves etc. We're really thankful for that and it's made our move much more pleasant.

- Jason and the painting crew came through once more to touch up all the little dings made during the move and frantic days leading to our getting in the house.

- the deck work started with concrete being poured for the main pillars and the sub structure went up Friday. If all goes well, we should have a deck out of the family room patio door on Monday! This is the last major project being tackled, everything else is just wrapping up.

- the landscaping crew continues to make good progress. They completed the irrigation systems across the property, finished the bender boards for the planters and laid out sod which we sourced from the Grass Farm in Gilroy. We used their special blend of primarily fescue grass. The sod was well needed, providing a welcome escape from the mud. All that is left on the hardscape is to finish a wall hugging the house under the deck and complete some stairs cut into it. Next up will be plantings.

Speaking of fences, we had a nasty wind storm here the day after Christmas and it ended up blowing down one of our fences. We'll have to change that one early now and have talked to our neighbor about it, who seem willing to split the cost. At the same time, a huge gust of wind ended up lifting our landscape trailer and crashing it into our car causing some nasty bumper damage. I've never seen a gust like that and it makes you appreciate what it muct be like in a hurricane.

We have yet to connect our solar system to the grid. We've been disappointed of late with Ready Solar. The latest gaffe was that we have the wrong inverter designed into our system. We expect to have the proper one in couple of weeks although we've lost some 6 weeks already on hooking our system up and generating power.

Aside from this, the project is coming to an end. It will be sad to see the crew leave but what an awesome house they have left behind for us to enjoy! And what must be a record build - 7 months from complete tear down to move in. We could only hope to build another house with Structural FX!

The Office is Up and Running!

I'm typing this blog post from my new home office! Yes, we did a partial move in over the weekend and it's been great getting set up. It's been pretty much a seamless cutover with phones and Internet both working perfectly. The downstairs part of the house has a little work left to finish up but that will be done soon enough.

This week the carpet went in. This was carpet we had purchased from Owens Wholesale Carpet in Dalton, GA. Recall a few posts ago we had been strongly warned by our local carpet shops against buying our carpet this way - we won't know what we're getting, there will be no servuce, blah blah blah. I have to say, we could not be more pleased. All the carpet and pad was in perfect order. The installer, Paul Ondricek, really knows his stuff on seams. He is about 90% done now with just the stairs left for Monday. The job took about 4 days in all.

While carpet was going in, Barney of Structural FX finished up the cherry crown in the kitchen. I was pleased with their recommendation to make it a little wider than the standard Thomasville crown piece, adding some light rail that ran around the tops of the cabinets and some filler between the light rail and crown. It makes for a nice thick craftsman like band all around the kitchen. By the end of the week, the last of the cabinet doors were up and the kitchen was given a good cleaning and ceremonial unwrapping of the granite island.

The door handles also went in throughout the house. I was able to mobilize the shorter 2 3/8" backsets and full lip strike plates air shipped from Omnia. Home Annex were quite good at turning all this around. These all fit perfectly and I just shipped all the replaced parts back for credit.

The painters returned on Friday and continued through the weekend touching up. They say they will be done inside by Wednesday. There is still a lot to do outside but that can continue into the new year without disrupting us.

We put the new TV up in the media room and Brian framed it up nicely with help from Charley who did some rapid plaster work there and in other parts of the house. The Harman Kardon AVR arrived and I tried hooking it up this weekend but the instruction manual is a little complicated so it will have to wait before we get the full surround sound effect.

The staircase rail is still in process. Joe the wlder was here (a friend of Brian's from United) to build us a custom metal frame. It's ready to go for powdercoating Monday and then back to install the cable rails hopefully in time for the move in.

The outside yard has been a mud pit the past few days as the rain was quite heavy all week. Despite that, our outside crew was able to make some progress on bender board and irrigation system. We hope to bring in a load of sod on Thursday - a green Christmas.

In fact, if all goes to plan, we will be officially moved in on Friday! There's a lot of little details to finish inside but I am confident in the Structural FX crew. We loaded up the fridge again with snacks and drinks to keep everyone going.

2 Weeks to Move in

We arrived to a nice surprise on Friday with the Structural FX crew putting up Christmas lights around the house. All nicely connected into the eaves outlets and on the electronic timer controlled from the garage. We had also re-loaded up the fridge and snack bar to keep them all going in these last few weeks of intense finishing work.

It was another blazing week of interior finishing work and bonus exterior landscaping while the weather has held up here. I'm writing this now as it's just pouring outside and our street is like a river. The rains have finally arrived to the Bay Area! Here is an update on this week:

The last of the upper cabinets were installed in the kitchen and we ran copper tile along the entire backsplash. The tile needed a special epoxy grout but hardened nicely and at the same time sealed the copper nice and shiny. Charlene baked Christmas cookies for the crew on Friday for the first time using our Thermador double oven and dropped off a case of beer and taco chips with salsa. Up for next week is to finish the crown moulding and trim.

The carpet arrived from Georgia. I had purchased this from Owen Carpet in Dalton, saving at least 30% over what we could get it here in the area. They held it for about a month until we were ready and the day has at last arrived. The garage was cleared out and it was dropped off in there. It actually takes up less space than I had imagined but that is probably because the carpet is so tightly packed up in the rolls. The installer Paul Ondricek will be here Monday. All the room are ready and cleaned up.

The Shoji cherry door from Cherry Tree Designs in Montana was installed in the dining room. The door and track look great and make for a nice transition that will match up with our cherry dining room set. You can also see it from the front door which makes for a grand view.

The interior speakers got put in the ceilings. We went with Bose 191 which have a pretty big box but fit nicely between the trusses. All the speaker wires come in to one point in the family room and we also ran them down to the media room in th eventual hope that we will be able to hook everything up to a media pc with remote control. I don't think the technology is there yet to do this properly and cost effectively but should be in a couple of years. We would want to try to re-use as much of our amplifiers as possible when we do this. As for the media room, we were not able to get speakers in the ceilings due to the TGI joists which are very tight. We will place exterior mounted Cambridge Soundworks Newton speakers around the room.

The Omni stainless door "dummy" latches were put up throughout the house on the closet doors. There was a mixup on the strike plates and backsets for the passage and privacy latches and we are getting replacement parts sent over from Omnia. That has been a challenge as we had bought these on the Internet from Home Annex which meant first filling out a return authorization form, then spending a couple of hours on the phone with the customer service/sales group to get the right parts and air shipping. This is a drawback of Internet orders. If you don't get the right thing, it can be quite a frustrating exercise dealing with returns and exchanges. Anyhow, the right backsets are the 2 3/8" type, which are pretty standard for most doors, not 2 3/4", and the strike plates are "full lip" not "T" shape. I was surprised Homeannex had no option on their e-commerce site to specify full lip or T, very annoying.

The hot water heater was hooked up. Candice our plumber was back for a few days working on this and connecting the Jacuzzi which got dropped back in the newly grouted granite tile bath area which looks great. Barney did a great job laying that tile and polishing the edges with a grinding wheel. Trent was busy hooking up all the faucets and bathroom accessories, which really tie the look all together. We are very pleased with all our choices on the these.

On the outside, Brian was able to mobilize a crew of day laborers to do more work on the back garden walls, spread some dirt around with a bobcat (equipment thanks to San Mateo Rental), roto till the entire property and demolish the last remnant of the old house - a section of the white picket fence that was being used to hold up our mailbox. I told the mailman to deliver to our house now. We put our numbers up in a hurry, both lighted and the Design Within Reach ones we bought for the entrance area. The day laborers also dug the main trench for the water pipe that will feed the fire sprinkler system.

Next week's list: carpet installation, finishing the kitchen crown and trim, finish the half bath slate vanity/sink and painting touch ups. If the weather clears, they may tackle the deck and finish the garden wall and stair areas. I hope to also get the trenches doug for our sprinkler system and put in the bender board for demarcation of the flower beds so that we can finish bring in fresh grass sod. Our fireplace slate still has not shipped yet but is expected to be done this week, a month later after our delivery disaster.