Solar update

The solar system went live on April 18th, so we’ve had it for about 7 weeks. It’s been interesting, as my awareness of energy consumption has increased dramatically with the monitoring data from the system, and we’ve changed some habits and practices. Also, as “technology” goes, this is dead level easy. Once it’s installed, it just quietly does its job. There will be more later in another post on this “quiet” statement; one side effect is increased RF noise which creates some HAM radio issues.

Now for some details. First, let me say that the system isn’t complete yet, as the Tesla Powerwall battery has not been installed, since it was on backorder. It’s arrived now at the installer, and should be in by the end of June. Also, note that my utility does not support Net Metering, so I have to consume all of my generated power in real time, or store it. Since the battery is not currently in, I’ve left a lot of energy on the table. As we have looked at the consumption patterns, it’s easy to discern when the HVACs run, the water heater runs, the dryer, and other things turn on. We’ve made some adjustments, replaced some lights with LEDs, and we take shorter showers. One of the big items is the battery electric car, a Chevy Bolt. It runs entirely on electricity and has a massive 60 kWh battery. One of the big adjustments we’ve made has been in how we charge the car. Instead of charging as fast as possible, at 7.2 kW per hour, I’ve slowed down the charge to about 40% of that, 2.8 kW. I’ve also set it to charge from 9 to 4 when the solar output is at its highest. The JuiceBox charger makes this easy to manage thru its app. If I need to use the car for long drives on consecutive days, I can increase the rate and draw more from the grid. But if not, let the car capture the sun! The Powerwall, when in, will capture any generated power not otherwise used, and can use that energy after the sun goes down, or for backup power if the grid is out.

So what are the results? We were away from home for 3 weeks in May, so that skews the data, tho the HVACs were on, and we had some construction underway. Here’s the picture so far:

The system has captured, as of this snapshot, 643.55 kWh of power over 54 days. That’s about 12 kWh per day. However, it’s a mix of very low days where 14 kWh Powerwall would have grabbed much more power had it been online, and 20+ kWh days in late May and early June where car charging and HVAC grabbed virtually all generated power. June production, over just 6 days, is over 135 kWh! The projected production with the Powerwall is approximately 16 kWh per day on average.

The car has received 300 kWh over this same time (out of 1.62 mW total consumption), but I think that is slightly understated due to a couple network glitches. Here’s a graph that shows the car charging at 2.8 kW from 9 to 4, with HVAC use skewed late in the day. Note that the house has three relatively old and inefficient HVACs and when these are replaced, the total consumption will drop significantly.

So what’s the bottom line? I think that with the Powerwall the projected production of approximately 5,900 kWh annually is very doable, and I’ll probably exceed that. My savings should be on the order of $600 per year, at current power prices. Assuming modest inflation in grid power, it will pay off in 20 to 25 years. But it’s the right thing to do, and I’ll also have an emergency power system. Also, the instrumentation and data will help to shape conservation efforts over time and that is also a hidden savings.

A fortnight with solar panels

Well, it’s actually only been 13 days, not two weeks, but close enough, since the installation started a couple days earlier. Our system was installed by Southern Energy Management, based in Morrisville, NC, who did an outstanding job. The system installed is composed of 15 REC TwinPeak 290 panels, 11 facing due south and 4 facing west, for a nominal capacity of 4.35 kW. The plan had been for all to face south, but the roof layout and potential for shading dictated the placement. With some of the panels facing west, the peak capacity is slightly less, but the “tail” of power generation is longer in the afternoon, due to the west-facing panels. These are connected to a 6000 W single-phase SolarEdge inverter. I asked for an inverter of higher capacity in case I ever wanted to add a few more panels.

Actually, the system isn’t complete yet, as we’ve got a Tesla Powerwall on order (on backorder, like everything else Tesla makes 😉 ) but telemetry from Southern Energy is that we’ll get it in August, so that’s at least on the roadmap. The Powerwall is an important part of the installation as the local utility does not offer “Net Metering.” This is the arrangement with your utility where you can sent your generated but unused power to the grid and you receive payment for each kWh that you send to the grid. So, we have to use all the power we generate, or it evaporates. That’s where the Powerwall comes in. It has a 13.5 kWh capacity, and absorbs power when you are not using it in the house. The solar system feeds the Powerwall, and the Powerwall then supplies current to the house at 5 kW continuous, 7 kW peak. It will supply power when the sun is down, or if a cloud passes over when a large load comes online. This should enable self-consumption of most of the power generated by the panels.

Currently, we’d be wasting a lot of potential power without being smart about when to run various appliances. For example, run the washing machine, dryer, and dishwasher between 10 and 4 (DST). Take showers mid-day as well, as the water heater is a big power draw. But the big thing is to intelligently manage charging of the electric car. It can hold 60 kWh of power, far more than can be generated, and can accept a charge at up to 7.2 kW. However, the JuiceBox Pro 40 EVSE we have for charging can set various charge rates below its 10 kW maximum, and by spreading the charge out during the sunny part of the day (when you don’t have to charge fast), you can capture much more of the solar power. Here’s a graph that shows this clearly. The JuiceBox is set to charge at a maximum of 3.6 kW.

The large “flat” peak is the car charge from about 0930 to 1530, for about 6 hours at 3.6 kW, or around 21-22 kW of demand. Note, however, that the system peaked at about 3.6 kW for only a short while at “noon” (1 PM DST). The demand from the car, combined with the baseline load of about .5 kW was more than the power that could be generated. The sharp peaks are the water heater, or at 0800 coffee and breakfast, and at 1730, cooking dinner. However, the solar still covered 54% of the house demand, and captured nearly 24 kWh. The Powerwall will work in the same way, capturing power left on the table to cover the overnight hours you can see on each side of the graph. We don’t charge the car every day, and this is where the automatic charge of the Powerwall will be very helpful. Without charging the car, usage that would be covered is more like 5-8 kWh. This, of course, is in a shoulder season without the heat pumps running, and we’ll see how that impacts overall consumption. The Powerwall, however, will ensure that we grab at least 20 kWh or so each day when the sun is shining.

Stay tuned for future analysis once we get the Powerwall in place. It’s really interesting to see how you use your electricity, and it can prompt changes in behavior.

Universal remote control

When I did a Facebook post on this topic a couple days ago, I promised to write it up a bit more thoroughly. So, if you read the FB post, you can skip this, or not. 😉

The entertainment systems I’ve cobbled together over time have worked, but only with directions written and taped to the bottom of of the 4 remotes on the end table. Needless to say, it’s not been a recipe for marital harmony. Let’s just say that I have a higher tolerance for a multi-remote control system than my dear wife!

This year in early March, one of my sons (who is more of a geek than me) suggested after a visit that it was too complicated and he agreed with his mother. He showed me a high end version of a Logitech remote, but I just couldn’t hang with the $250 price for something I was sure would not work. Not much happened until I was headed to a conference for a few days…and it was made clear to me that something needed to be simplified!

So, when I returned I looked again at the Logitech remotes and saw that there was a simpler version without a touchscreen remote. I ordered the Harmony Companion, and it brought harmony to the house!

It truly works! I set up 5 different programs – one to set up for music streaming from Alexa, one for the TV (we use an LG TV, OTA programming, and a TiVo), one for AppleTV, and two for Roku, one to launch HBO Now, and one to launch Amazon Prime. I have a Chromecast also in the Denon receiver (actually, I have three of them all in different TVs), but never use it so no program yet for that.

Programming the remote involves a set of “activities,” which are multidevice sequences of actions to set the stage for the activity. You can control lights, etc as a part of an activity if you have compatible tech, but my Smartlife WiFi outlet sockets don’t work with it. It does apparently support and understand remote commands for just about any device with a remote control.

I did my setup on my iPad, and apparently that’s easier than the computer-based setup per the reviews. The UI allows you to select devices and actions as a part of the activity. The problem is that it doesn’t allow you to delete or move a step, though can add or modify a step. My TV sequence involved a bit of tweaking as when you turn on the TiVo and TV, the TV doesn’t sync to the HDMI input unless you do another source switch a few seconds later. So I had to turn on the TV, the receiver, the TiVo (with a different source), the delay several seconds (there is a delay command for just this type of situation), and then switch to the TiVo input. The iPad app crashed several times while I was doing the activity setup; it’s the weakest part of the system.

I also set up the Alexa skill and sync’d the accounts. This is another area that doesn’t provide as much control as I’d like. When you set it up, you get to choose keywords used in the invocation, but there’s no way to edit this after setup, at least that I’ve found. It also takes a few minutes for the accounts to sync. But it works! “Alexa, turn on the TV” does so, and “Alexa, turn on Tunes” sets up things for Alexa to use the receiver. With the TV and other such activities, you can also tell Alexa to “turn up the volume on the TV” and it will adjust the receiver volume setting.

The Companion remote has three activity buttons, shown as “music,” “TV,” and “movies” but using icons. You can short press or long press the button and that will give six activity invocations.

The remote talks to the base with Bluetooth, and the base emits IR/RF/Bluetooth to control devices. Per the directions, you can place the base with other components , and the IR reflects off the room and does not have to point to the targets.

So, this really does work. This particular version controls up to 8 devices. It sells for $100-$130 and has brought “harmony” to my house!

A day in the life of an EV

Well, not a day, but, with apologies to Solzhenitsyn (damn, I’m glad spell check jumped in here!), it gives me an excuse to extol the virtues of driving an EV. Don’t get me wrong, I like my Silverado, and it does a great job pulling the boat, hauling other trailers, hauling dogs, driving on the beach, and so forth…but I sure do wish GM made electric trucks! I didn’t have but one errand to run today, just a 2.5 mile (one way) trip to the dentist, but I sure do love to drive the Chevy Bolt. Heck, it’s not a Tesla in Ludicrous Mode, but press the sport button, push the accelerator, and you will zip you into traffic with the instantaneous torque only an EV can offer. Zip up to 45 mph, slow down to 35 in the EI business district, back to 45, then whip around the new roundabout (using one pedal driving with huge regen braking) and over to the dentist. Reverse it going back, and I used 1 kWh, about 9 cents, for the 5 miles…and fun to drive.

Need a new car? Do yourself a favor and check out an EV.

Another nice day with Clearwater trout

The first day of Daylight Savings Time means getting up early, more so when you have a two hour and 45 minute, 155 mile drive. A lot further than when this was only 15 minutes from the house, before we moved. My alarm went off at 5:15 so I could make coffee and get out the door to meet Sam at the EV charging station at Durham Regional Library, so I could get a charge on the Bolt while we fished (used 95 kWh for the round trip, so with 60 kWh battery, with temps in the 40s, I needed several hours of juice). Sam picked me up at 8:30, and we headed to Clearwater, for the TU-sponsored stocked winter stillwater trout fishery. It started very slow…only one guy (of 8 rods on the lake) was catching fish, and he caught several while I was watching. I asked him what he was using, and he was fishing a dry as a soft hackle fly, just below the surface. I did the same, and promptly caught a couple nice fish.

Sam was on the other side of the lake, so I walked around the lake to where Sam was fishing, and suggested we have lunch and debrief. We ate, and then went back to to casting stations where the action had been. He promptly caught a nice one!

We then figured out that olive wooly buggers were the ticket, and over the afternoon we each caught a dozen or so, big strong fish, 16-24″. It rained on and off during the day, but the fishing was good in the afternoon and that made for a great time. Good fellowship and lots of trout. A great way to spend a late winter day.

Electric dreams and clean beaches

What does a picture of a Lab fetching a frisbee from the surf have to do electric dreams? Just indulge me for a bit…we’ve been driving the Bolt for two and a half months now, and I’m more convinced than ever that EVs can work for the vast majority of families, particularly if you look at one as a local or “regional” car. Yes, we still have two internal combustion vehicles for the time being, but they are being used for special cases. I have a Chevy Silverado crew-cab pickup I use for hauling the boat to the ramp, and as our long range trip car. We’ll keep the truck for its special abilities. We also have the 2006 Chevy Equinox that Jan drives once per week to Mebane to visit her mother in assisted living, a 400 mile round trip, and we need this vehicle as long as she’s making that trip. For everything else, we drive the Chevy Bolt. We drive to Wilmington, to Greenville, to Jacksonville, to Beaufort, to Morehead, or just to Swansboro. Now that the weather has warmed, we’re getting 5 to 5.5 miles per kWh (up from 4ish mp/kWh in cold weather), for nearly a 300 mile range. Think about the percentage of your drives that fit a 125 to 150 mile circle. I’ll bet it’s pretty large. Need to go further? Keep a second car, or rent for trips. More EVs are coming to market with decent range and dropping prices. If you think about it, you could use an EV for most of your driving, too. Teslas are great if you can afford one, but if not, there are a growing number of options. Look at EVs. Ask your friends who have them. I’ll bet you can make it work, and it’s good for the planet…let’s make drilling for oil and gas a moot point, and keep our beaches clean…and that will keep that dog happy in the surf!

Chevy Bolt after one month

We bought our Bolt on December 12th, just over a moth ago, so I thought I’d take advantage of a lazy, cold Sunday to jot down a few thoughts.

First, overall, both Jan and I are quite pleased. We’ve put about 1400 miles on it. That’s more than we’ll usually drive in a month, which I’m guessing will be more like 1000 miles. It drives very well, and matches stated economy specs. We routinely get well over 4 miles per kWh on running around with trips that are for local (50-60 mile round trips) shopping or errands. We’ve driven from EI to the RTP area twice (175 miles each way), including freeway driving. Once, we overnighted, and then I drove it for a day trip to go fishing on January 13th. On these trips, we got 3.7 to 3.8 miles per kWh. However, it’s important to note that we tried not to exceed 65 mph, even in a 70 mph zone. Also, we ran the heat sparingly as this can reduce mileage by several percent. Instead, we used seat heaters and the heated steering wheel. The heater works very well, you just see the cost directly, since heat is a waste product in an internal combustion engine (ICE). By way of comparison, today we drove to Sam’s Club in Jacksonville, a 54.3 mile round trip, urban driving with about 20 miles at 55-60mph. Used 12 kWh for an average of 4.5 miles per kWh.

The Bolt is fun to drive on curvy back roads, since it has a very low center of gravity, great regenerative braking, and excellent acceleration. A key to good efficiency (higher miles per kWh) is to accelerate moderately from a stop and not use the 200hp engine to show off its capabilities.

A sidebar here on regenerative braking. While you have brake and accelerator pedals, there are two modes to drive an EV, traditional and “one-pedal.” In one pedal mode, it goes when you push down, and brakes (regenerating strongly) when you reduce pressure. This gives excellent control for sport driving and you almost never need to use the friction brake. For freeway driving, however, I shift to traditional mode, especially if I’m going to use cruise control.

The Bolt is roomy, though the seats are narrow. Frankly, if you have a big butt, you won’t like it. I’m 6’5″, 230 pounds, and I’m ok. But a stockier person might have issues. It’s roomy for 4 people, and can seat 5, and works fine for the granddaughter’s car seat. The hatchback-style trunk is good for groceries, and will even hold 2 Labrador retrievers for 3 hours, with the backseat folded down.

Our JuiceBox EVSE (Electric Vehicle Supply Equipment) works well. It’s a misnomer to call it a charger, technically, as the car contains the charger and the EVSE is a smart switch. One thing that was interesting is that in very cold weather low 20s and below, the car will consume power periodically to keep the battery pack warm. This is very evident in the charging logs from the JuiceBox. The opposite takes place in very warm weather, where it cools the battery. The heating process seems to be as much as 2 kWh every 4 to 6 hours. Obviously if you have the car in a garage this is mitigated. The JuiceBox provides the Bolt with its maximum of 7.6 kW input, for an effective rate of about 30 miles per hour. Remember this relates to your efficiency, so that at 3.7 miles per kWh it recharges 28 miles per hour, and at 4.5 miles per kWh, it charges 34 miles per hour.

I’ve just charged the car once at “station,” which in this case was a free charge at a library in Durham, with all other charges being at home at EI, or using the dryer plug in Chapel Hill (but that house is now sold, and we’ll be out in February) and Winterville. I have charging credentials with EVGo, ChargePoint, and Greenlots. I’ll use them at some point. Again the key is that charging an EV is not like going to a gas station and being back on the road in 10 minutes. You just have to think differently about refueling, with the ideal being an overnight stop with an EVSE.

However, again, the key is that an EV will do a heckuva lot of the things you do, and with an ICE 2nd vehicle or a rental as a backup, you can cover the other use cases.

Clearwater 2018

Sam and I met at Camp Clearwater for a day of trout fishing today. The local TU chapter puts 1,500 pounds of trout into the lake each year for a winter trout fishery (it’s too warm for them to reliably survive the summer). It was a cool, blustery day with temps dropping all day into the 40s on stiff northwest winds. However, that’s better than last weekend when the lake was frozen over!

We arrived at 9 (this is 9-5 fishing, with a TU lake warden in attendance) rigged up and started fishing. I tried a Chili Pepper, a copper colored wooly bugger. Sam used a black bugger. We went thru many flies and all around the lake with only one fish between us by lunch, a 10-inch largemouth I caught on a black bugger.

We ate lunch in the camp office, sitting by the heater. After lunch however, our luck changed. Sam and I each hooked several fish, all big fish, 16″ or better. I caught one that was easily 24″ long, and fat like a football. That one gave me quite a fight before Sam netted it.

We caught our fish on the Chili Pepper and small black buggers, exclusively.

Here’s a shot of Sam with a nice fish

It was a great day of fishing, catching and fellowship. Glad we have another day scheduled this season!

2017 EV sales continue to rise

Saw a good statistical summary of electric vehicle (EV) sales for 2017. Nearly 200,000 battery electric and plug in hybrid vehicles were sold in the US in 2017, up by 26% from 2016, and 1.6% of US sales in December. Estimates are that we’ll see sales of 300,000 in 2018, depending on the Tesla Model 3 rampup, and vehicles like the new Nissan Leaf, and the Chevy Bolt.

The EV is probably still not an “only car” for most folks, but as a second car, it will fill a lot of niches with current and emerging products.

EV chargers

Saw an interesting article on Level 2 and DC fast chargers, with a summary of chargers by state, here. I was interested to see both a good number of chargers in NC, as well as the ratio of DC chargers. The page says the total includes public and private chargers, as well as the Tesla network. What it doesn’t say and probably doesn’t include, are privately owned chargers but made available thru networks like PlugShare. We installed a JuiceBox Pro 40 (a Level 2 charger), which at 40 amps, is faster than many commercial Level 2 chargers. Like many other EV drivers, I’ve listed this on PlugShare in case anyone is in a bind and needs a charge. EV chargers are not as ubiquitous as gas stations, and are nowhere as quick, particularly the Level 2 chargers, but there are more out there than you might think.