Author Archives: joel

About joel

Retired Higher Ed administrator, flyfisherman and geek

New Year’s in Tucson

We are big fans of Rick Braun, smooth jazz trumpeter, and every year he does a New Year’s Eve show at the JW Marriott Starr Pass in Tucson. Well COVID be damned, we booked the trip back in the early summer of 2020. We’ve done trips with Rick before, including two European river cruises. Now realize that this was in the lull after the Delta variant, and we’d just gotten back from a trip to Glacier NP at the bottom of the COVID trough. So we signed up for NYE and booked flights. Well, we were feeling pretty good about this until Omicron came along in the late fall. The show itself was vaccine-required, but we had some trepidation when we set off, even tho Pima County AZ had implemented an indoor mask mandate.

Well, we are now 3 full days past our return flight, and are feeling like we made it safely, no symptoms of Omicron. We are well past the NYE concert/dinner/party, which was our biggest concern.

Travel still feels a bit odd, but we flew 1st class which gave us more room. We had a long layover going out and stayed in the Delta Sky Club in ATL. The party was at the JW Marriott Starr Pass, and after that we had an AirBNB on the northeast side of Tucson.

Here’s a shot from the back door of the AirBNB

We hiked in the west and east sections of the Saguaro National Park

We drove up into the mountains to enjoy the snow that fell on NYE

We did some hikes almost out the back door of the AirBNB

We visited the wine country of Southern Arizona (who knew that there were great wines between Tucson and the Mexican border!?)

All in all, a great trip to the Southwest and fun to travel again. Cross our fingers we escaped Omicron! Vaccines and boosters and masking! Here’s to more travel in the future!

A two year retrospective on solar energy

We are seven days from the end of 2021 with a stretch of sunny weather ahead, and I’m struck by the overall similarity of my power usage and solar production in 2020 and 2021.

First, let’s take a look at the results here with summary graphs from each year.

We’ve used slightly less power (300 kWh) this YTD than last year, but most of that difference will be made up in the next week. Similarly, we’ll make about 100 kWh or a bit more over the week. We’ll have generated 63% of our power over this biennium.

Next, let’s look at weather and monthly grid import.

Utility power consumption net of production

You’ll see that this is a very mild climate, with average highs under 90, and average lows generally above 40. Note that March, April, May, and then September, October, and November are the lowest external consumption. These are the shoulder seasons when HVAC usage is low, and especially in the spring, when production is high. High sun angle in the spring and cool temperatures are perfect for solar production.

For context, this is a 2100 sq ft house, built in 1993. There are just two of us here, and we work had to conserve energy. It’s “southern beach house” style, sitting up on 10 foot posts with a carport and utility rooms under. It has 3 HVAC systems, as a large addition was done in 2002 and it just worked out better to do that. We actually like this as having 3 zones gives a lot of flexibility for temperature management. We have a propane stove, but all other appliances are electric. All lights are LED, and we keep the temperature at 66 in the winter, and 77 in the summer. Baseline house load with no HVACs, water heater, or dishwasher running is 400 to 800 watts depending on which fridges and freezers are running). We could improve our curtailment of vampire loads. We get a lot of beneficial passive solar heat in the winter (love those sunny days that warm the house!), but that’s a double-edged sword with too much summer heat, too.

Now, let’s look at some of the differences in production and aggregate (not net) consumption on the graphs below. December 2020 was much colder than this year, and the difference in power imported is due to that and not just that December 2021 is missing a week. Summer import in 2020 was less than than in 2021. But generally, the cycle of high AC in the simmer and early fall with heat in the winter dominates seasonal consumption differences. The left graph below is 2020, and the right 2021.

However one thing that doesn’t show here is EV charging, which was about 50% higher in 2021 than 2020. In 2020 we put 1.4 MWh into the car. In 2021, this figure was 2.2 MWh. As a rule of thumb you can figure 4 miles per KWh. This home charging is not the total energy use, as this does not count any public charger use or use at the home of friends and family. I have better figures for 2021 on this than in 2020. Public charger usage was about 750 kWh and other charging was about 300 kWh, for an additional 1.05 MWh. This 3.25 MWh is consistent with the 12,800 miles on the car this year and an average of 3.9 to 4 miles per kWh. Without home EV charging in 2021, instead of 63% of energy, we’d show 77% of energy generated.

Our installation is 6.09 kWp (21 REC 290 watt panels) and one Tesla Powerwall configured for zero export. However, we have winter tree shading (in our neighbor’s yard) to the south, and only one row of panels is unaffected. I have 4 panels facing west instead of south, and another set of panels that gets shaded by parts of the house in the winter. My educated guess (and comparison with the results from the NREL PVWatts calculator) is that I’m losing about 1 MWh each year when compared to the ideal.

The bottom line is that rooftop solar can make a big contribution to meeting our energy needs. If you have a house with a southern exposure on the roof, you should look into it. Some utilities and rate structures make it easier and quicker to pay for the system, but it really works!

Clearwater trout, 2021 edition

I’ve badly neglected this blog, with no posts since spring 2019. But heck, let’s put up a fishing post!

I met Sam at Clearwater Lake near Chapel Hill on Sunday December 5th for one of our 2 annual Clearwater fishing days. It’s a winter fishery only, as central NC is too warm to keep trout all year. The TU chapter stocks it a couple of times, starting in November. You reserve a slot ($45 per day) and there are 8 or 9 fishermen. Sam and I like to fish the dock so we can talk and catch up with each other while we fish.

The fishing is always good but the catching can be tough sometimes. This is not always easy fishing. But we’d had a few days of warm weather and the fish were on their feed. Each of us caught 15-20 nice rainbows, strong and feisty. Caught many on Sam’s well tied wooly buggers, then switched to Chunky Chernobyls with Sweet Things as a dropper.

Shad, spring 2019

Hickory Shad

Hickory Shad

The last couple of years weren’t good for making the trip to Weldon to catch shad on the Roanoke River. Either the water was too high, or too cold, or the few good days didn’t mesh with my schedule, or Sam’s. However, we finally got a beautiful spring day when we could both make it, and the fish were there.

I drove from Emerald Isle and met Sam in Weldon. It’s about a 2 hour 45 minute drive for me, and about 2 hours for Sam coming from Durham. We met at 10am. I brought the Mad River canoe with me, as our plans were to fish from the rocks, and we wanted to get to the far side from the boat ramp. We got in position by 11, and fished until just after 3. The action was steady. We’ve caught more fish some years, but rarely so many big strong ones. We caught fish on orange flies, pink flies, green flies, and even some on shad darts on the spinning rods, too.

Sam with a shad on the line!

Sam with a shad on the line!

Each of us landed 20+ fish, though unusually I caught a few more than Sam 😎

Joel with a nice one!

Joel with a nice one!

The beers were cold, the day warm, the fishing good, and we enjoyed watching the ospreys plucking shad out of the river.

After our arms were tired from catching fish, we loaded up the canoe, ran the rapids, and head back home. A great day…

Energy consumption and production

I’ve been sitting this evening, reflecting on energy and the Dunn household. Since our solar system went live on April 17, it’s produced 2.28 megawatt hours of power (equivalent to 2,280 pounds of coal!). The potential production was probably 200-400 kWh more, as we don’t have net metering and the Powerwall was not installed until early July. Our consumption during this same period was 6.86 megawatt hours, so the solar system produced a third of the power used by the house. However, another consideration is that our all-electric car, a Chevy Bolt, used 659 kWh from home charging (about 3,000 miles of driving) during the measurement period. That’s less than normal, as we were traveling for several weeks during this period. If you factor this out, the solar covered about 37% of the other household consumption during a hot summer with the three air conditioning units running many hours per day. During the next 3 months, I expect the solar percentage to increase substantially as the air conditioning load drops, before heating season begins in December (hey, it’s usually mild here).

Whether you reduce your power consumption by changing to LED bulbs, installing new windows, doors, HVAC systems, or by generating some of the power you need, we can all help to reduce fossil fuel usage and reduce greenhouse gas emissions. Climate change is real, and together we can make a difference!

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.