partial_accumen

I don’t currently have a large scale system; I’m currently running my fridge and a few other things off of a portable solar/battery setup, as part of researching a whole home system.

I had already done the research I needed and was ready to put in a larger house-attached grid-tied system slightly before the current generation of portable battery/panel setup came out. For your situation, I agree you are taking the right approach.

I’m on a standard rate plan, I pay 14c/kWh round the clock.

Can I ask if the 14c/KWh is the rate you pay for generation only or the whole cost to deliver 1 KWh to your house (transmission,distriubtion,generation,customer connection plus fees). Put another way, if you consumed 1000KWh in a month would you have exactly a $140 electric bill?

The ToU price and schedule for my region looks like this:

Peak is ~29c/kWh, Off-Peak is ~11c/kWh, Discount is ~7c/kWh. So I could save money if I just switched to the ToU plan and threw my main breaker 3 hours a day.

My local energy company’s exporting solar program is bad and about to get worse, to the point it’s out of the question. I’m not going to sell them power at mid-day for 3c/kWh and buy it back at damn near 30 at night.

Ouch, so even on the fixed rate power plan you essentially 4.67:1 net export (as in you have to export 4 KWh at midday to import 1 KWh any other time of day)?

So the only real winning strategy here is the “ToU + battery time shift” and since the equipment needed to do that almost certainly has plugs for solar power, might as well put up some panels. Buying power at 7c/kWh in the early morning, generating your own power and not buying anything during the day while power is 11c/kWh, and then using the power you bought earlier when it costs 29c/kWh is the move.

Yep, in your state, I agree TOU+battery is likely the best way to go limiting import as much as possible.

Not as useful on a heat pump where you want to generally run the same temp 24/7/365 to give the heat pump the most time to extra energy from the outside air and avoid large temperature swings triggering power hungry electric strip backup heating. A programmable thermostat is still useful for the occasional vacation hold though.

This isn’t congruent with my understanding of how heat pumps work. Electric strips are going to kick on in extreme cold if/when the heat pump can’t keep up, or for defrosting the outdoor unit. Every heat pump I’ve used, unless they frost up, will happily heat a house to 80 degrees from 32 without kicking on the emergency heat until and unless it needs to defrost.

For modern heat pumps your experience is mostly still applicable. The exception is the “comfort” settings most vendor thermostats incorporate. If a temperature increase is indicated by the operator above a certain set point, the system interprets this as a call for rapid heating and will run the condenser at 100% but also kick on electric strips to reach the called for temperature much sooner.

I’ve never personally seen one kick on heat strips simply for increased Delta-T, not without manually putting it in EM-HEAT mode.

I don’t currently own a heat pump, I have an air conditioner and a condensing furnace.

When we bought this house it had natural gas furnace too. Not only was the gas expensive, but during the warmer months the minimum require “connection fee” continued to get hit with price increases even when zero gas was consumed. When we finally replace the heat pump the connection fee was $40/month. My neighbors tell me its risen to $70/month now and none of that money goes toward consumed gas.

My long term plan is to have the air conditioner replaced with a heat pump, and keep the furnace for emergency heat instead of strips.

I considered a dual fuel setup like that, but the economics of the connection fee negated any value. I’ll be the first to say that my January and February electricity bills are very high, but all of the saving from not having natural gas, and being able to heat with solar generated heat pump in the spring and fall very much still make it financially worth it for this setup.

I recently learned that in North Carolina, if a given heat pump system is calculated to keep the home up to a certain temperature on the typical coldest night in the county, backup heat is not legally required. Defrost will be achieved by running the unit in AC mode, so you’ll occasionally get a blast of cold air from the vents.

I can run my heat pump in AC Defrost mode too, but the **Wife Acceptance Factor ** goes way down doing that so we run electric strips for the defrost cycle.

Neither my air conditioner nor my furnace run 24/7/365, both are duty cycle modulated, they turn on and off throughout the day and night to maintain temperature.

Perhaps I wasn’t clear. I wasn’t suggesting my heat pump is running 24/7/365, quite the opposite. Rather, the thermostat is set to a single temperature and, unlike gas heating, there is no value in lowering the thermostat temperature at night or when the house is unoccupied. The opposite exists, when running a heat pump reducing the thermostat temp at night means the heat pump has to run harder and longer in the morning when you want the house back up to temperature. Its less efficient because the limiting factor is the volume of air that can be moved through the outdoor condenser to extract heat from. If the option to save energy is having the house uncomfortably cold for hours everyday, I consider that a failure of an HVAC design. This is, of course, just my opinion though.

I’m three states north of you and we’ve been running on our Cold Climate Heat pump for two winters now without any gas heating. This unit can still extract heat for the house when the outside temperature is -15°F, but its running pretty inefficiently.

I know a decent amount about electronics, finance, and home solar.

Regional differences change the “best case” behavior drastically. For example, in my Midwestern state (with a still pitiful solar install base statewide), your list would be nearly the exact wrong ideal behavior. My state is about 10 years behind the leading states as far as solar installs and policy. So think back to California rules 10-15 years ago and that’s a pretty good idea what rules apply in my state which is quite an upside for solar home owners.

A time-of-use power plan from your energy company.

This would be a bad thing in my state. This would mean you would get paid the lowest amount of per KWh at the best time of production.

A whole house battery

Bad choice financially in my state. We have 1:1 net metering so the grid is the most cost efficient battery. I do have 10KWh of solar battery storage, but I don’t charge/discharge it daily and really have it for backup needs in case of a grid outage. Nothing about buying the battery is a good idea financially though in my state.

A smart or programmable thermostat

Not as useful on a heat pump where you want to generally run the same temp 24/7/365 to give the heat pump the most time to extra energy from the outside air and avoid large temperature swings triggering power hungry electric strip backup heating. A programmable thermostat is still useful for the occasional vacation hold though.

A few outlet timers

Not needed if not using TOU.

An electric car charger with timer or some similar solution

Generally not needed when not using TOU. Additionally, many EVs themselves have the timer built in so no need to have a timer on the EVSE. Full disclosure, I do charge EVs from midnight to 4AM because I have a separate meter from my electric company with a tariff that is “distribution fee”-free for every KWh for EV charging. This stacks with my 1:1 net metering, so I essentially get paid to charge EVs at night.

I am currently on a standard rate power plan, I pay 14 cents a kilowatt-hour no matter the time of day. My power company offers a time-of-use plan that varies between 29 , 11 and 7 cents per kilowatt hour depending on the time of day. The game becomes, buy as little power as possible during the 3 hours it’s 29 cents, and as much as possible during the 5 hours while it’s 7 cents.

I have no doubt you’ve chosen a good path for your state and electric company. You’ve put a lot of thought into optimizing it. My post is just highlighting that the rule to optimize against vary widely by region even in the same national borders.

Do you have a non-exporting solar system? If not what price to get per KWh during the various times of the day with your TOU power plan?

Thank you for this follow up response. I understand why the college does this now.

I feel for you that this means more work ahead for you. I wish you luck going forward.

The people at study department at 1st school told me they won’t accept grades below B, including what I already earned at 1st school. They just won’t count when I go there again, it’s treated the same as transfer.

Something is missing here.

Are they saying that [C and below is a failing grade] for every person that took that class forcing each of those people to retake the class? Or does the [C and below is a failing grade] only for students that didn’t score high enough to continue attending the school and the act they are telling you is your only path to rejoin the school by re-applying through the admissions process is the trigger for [C and below is a failing grade] for those classes?

The point is, they won’t even accept the courses I already passed (which are all below B except for English), because this rule is just applied universally.

Who cares if they don’t accept courses you’ve already passed. You’re not planning on graduation from 2nd school. You want to graduate from 1st school. When regular admissions open up again in the future for 1st school, you go there and transfer the credits in you earned at and 2nd school. Your prior 1st school credits (below As and Bs) will still be at 1st school so you won’t have to worry about them being accepted as transfer credits because you’d not be transferring them in from outside as the those low grade credits are already inside.

The only colleges taking students at this time of year are ones that have to do 2nd rounds due to low numbers, which very much is nothing IT-related.

Do you have nothing bu IT-related credits you have to earn for you degree? You’re completely done with 100% of your Math, History, Art, and Science credits no related to IT? If you have any of those non-IT credits you still need to earn, thats what you can do this year at 2nd school. Next year you can go back to 1st school and work on IT related credits again.

That one is also funny. There’s no official list.

Well I guess this is one area the USA is better. There are agreed standards that allow for nearly seamless transfer of student’s credits between large groups of universities and colleges.

The only requirement is A/B grade. If that is met, I can send a request to have those results accepted along with the courses’ syllabi, and then I’ll see based on their response.

Okay, so take courses at 2nd school, do well in 2nd school classes, and send the request to have those credits accepted at 1st school next year.

Otherwise it sounds like your best choice is to give up on school this year, and truly commit yourself next year. Any chance you have enough IT experience to get a junior role so you can at least be growing in your field while you’re out of school?

I’m only familiar with the USA regional accreditation process of schools which this doesn’t sound like, so I’ll have to ask questions about the rules in your system:

To study there again, I’ll have to go through regular admission procedure again, but it’s too late to sign up for next year.

Okay its too late to go through the regular admissions procedure for the school you studied at, have you confirmed its also too late to go through the regular admissions process at every other school your original school accepts transfer credits from?

If at least one school would let you go through the regular admissions process (not try to transfer into that 2nd school), then just attend that 2nd school taking different courses you need for your degree earning As or Bs grades, then transfer those newly gained credits back to your 1st school. So not this year, but next year go through the regular admissions process of your 1st school.

It depends on what you mean by robotic mowers. If you mean motors that drive the wheels and you don’t have to walk behind them (or sit on them), yes, these exist without any cloud service. However, if you mean autonomous, then I don’t think those are here yet. The non-cloud robot mowers use human held remote controls.

I can think of one that is autonomous and doesn’t require the cloud for operation, but does require the cloud for the inital setup and mapping. Once it has the map loaded in, it doesn’t need an internet connection.

That pretty well describes 1st generation robo mowers: law roombas.

Thankfully they’ve evolved significantly since then and are on 4th generation tech now.

Watching season 1: “I can totally believe they shot this whole show in an old hot tub factory”

Watching season 4: “I can’t believe they shot this whole show in an old hot tub factory!”