Simple home system

[nightrage]

According to my power bill, Including all appliances heat and AC included, I am using on average 40 kwh per day so just under 1700 watts if Ive learned the calculation correctly. I live in las Vegas and that is the highest amount of any month of the year.
So a 2 phase 48 volt all in one inverter providing 2000 watts would be plenty correct?

 

[FilterGuy]

According to my power bill, Including all appliances heat and AC included, I am using on average 40 kwh per day so just under 1700 watts if Ive learned the calculation correctly. I live in las Vegas and that is the highest amount of any month of the year.
So a 2 phase 48 volt all in one inverter providing 2000 watts would be plenty correct?

Not quite. Yes, the *average* power usage is 40000Wh/24h = 1666.7W. However, the usage throughout the day will vary wildly.

Example: Since you are in Vegas, you probably have a whole house air conditioner. I am pretty confident when it cycles on it will use much more than 2000W.

If you plot the wattage during the day, you would find that the peak power (Typically afternoon or early evening) is many times higher than the minimum power (Typically after midnight)

 

[nightrage]

Thank you so much for your response. Its most appreciated. So I need to get on the roof and find out the info on that beast air conditioner/heater. I did some more looking into my power bill. Last 12 months, 8300 kwh. With July August and September, 1033, 1162, 1137, respectfully. It appears that taking out the heater air conditioner my average is only 350 per month.

 

[BentleyJ]

In addition to the Average daily kWh's you also need to determine your PEAK demand. One way to estimate this value would be to add up all the Amperage Rating data from your major appliances and then decide how many of them you would need to be operating at the same time. Or you could put a home energy monitor on the 2 mains in your breaker panel. An Emporia energy monitor with 2 CT's is only $85.
What is your goal? Offset some of your electrical usage with solar, include batteries for emergency back up of critical loads or maybe the whole house, go totally off-grid. Grid-tie vs. self consumption. Its helpful if you can decide exactly what you need/want and what the budget is.

 

[Think About It]

According to my power bill, Including all appliances heat and AC included, I am using on average 40 kwh per day so just under 1700 watts if Ive learned the calculation correctly. I live in las Vegas and that is the highest amount of any month of the year.
So a 2 phase 48 volt all in one inverter providing 2000 watts would be plenty correct?

I would imagine that Las Vegas allows net-metering. What this means is that you can use the Power Company as a reservoir. When your system is generating more power it "sells" it back to the utility, and sells it to you when you're not generating enough power. If you generate 14,600KW of power per year you will break even. If you generate less, you will pay for the difference, and if you generate more the Utility will pay you.

Also, you need to generate on average 40KW per day. The amount of hours per day that you can generate solar power varies by season. But let's say for example you have 4 peak hours of sunlight, then you would need to generate 40KW in 4 hours, or 10KW per hour.

 

[Think About It]

In addition to the Average daily kWh's you also need to determine your PEAK demand. One way to estimate this value would be to add up all the Amperage Rating data from your major appliances and then decide how many of them you would need to be operating at the same time. Or you could put a home energy monitor on the 2 mains in your breaker panel. An Emporia energy monitor with 2 CT's is only $85.
What is your goal? Offset some of your electrical usage with solar, include batteries for emergency back up of critical loads or maybe the whole house, go totally off-grid. Grid-tie vs. self consumption. Its helpful if you can decide exactly what you need/want and what the budget is.

Totally agree. You should define your reasons and goals for going solar. Then design with those goals in mind.

 

[nightrage]

In addition to the Average daily kWh's you also need to determine your PEAK demand. One way to estimate this value would be to add up all the Amperage Rating data from your major appliances and then decide how many of them you would need to be operating at the same time. Or you could put a home energy monitor on the 2 mains in your breaker panel. An Emporia energy monitor with 2 CT's is only $85.
What is your goal? Offset some of your electrical usage with solar, include batteries for emergency back up of critical loads or maybe the whole house, go totally off-grid. Grid-tie vs. self consumption. Its helpful if you can decide exactly what you need/want and what the budget is.

Thank you Bentley Ive just returned to the states so Im picking things up again. I appreciate your comments. Ive looked at the Emporia energy monitor. Why do you recommend only the 2 CTs rather than the options of having each individual circuit monitored?

 

[BentleyJ]

Thank you Bentley Ive just returned to the states so Im picking things up again. I appreciate your comments. Ive looked at the Emporia energy monitor. Why do you recommend only the 2 CTs rather than the options of having each individual circuit monitored?

Based on what your needs for an energy audit, price and ease of installation the base model with 2 CT's will provide plenty of information. You can view data in Seconds, Minutes, Hours, Day, Mo & Yr. For example while viewing your energy usage in Seconds you could open the app on your phone and run around the house turning on appliances and easily determine how many watts each uses. When that's done just let the Emporia run for a few days while you go about your normal routine. Then view the data for Min, Hr, Day and will have a better idea how to size your solar system.
If want data from some of the individual branch breakers by all means get the 8 or 16 CT version if you don't mind spending a little more.

 

[ChrisG]

Emporia Vue is great. Almost have a year of data for my cabin critical loads panel. Know how many KWh of battery we need per day when here vs not. Also the 15 minute peak demand based on a year of usage gives me some direction of what my inverter sizing needs to be. However I know the 15 minute demand (1.19kw) is low because it does not account for surge of loads such as my well pump and worse case scenario if the well, coffee maker and microwave happen to be on at the same time which will be 5.5kw.

 

[LBART]

I have similar usage per day so I will follow along and see what you all say.

 

[Mattb4]

Pardon me but you seem to be mistaking an inverter as being a power source. Inverters take in DC and invert it to AC. You size your inverter based on your loads, both the running current and the starting current demands.

To power your home you need a power source that provides the loading requirements for the day. You mentioned 40kWh. If you are going solar that would be how much minimum your panels would have to produce during a day"s sun harvesting. You can look up for your area typical average solar hour production in hours over a day. For example I will use 5 hours. Thus your 40kWh divided by 5h = 8kW worth of solar panels.

This is just a start on the process and you will have a lot of work to do to setup a system that accomplishes what you need. Hope it gives you some food for thought.

 

[nightrage]

Based on what your needs for an energy audit, price and ease of installation the base model with 2 CT's will provide plenty of information. You can view data in Seconds, Minutes, Hours, Day, Mo & Yr. For example while viewing your energy usage in Seconds you could open the app on your phone and run around the house turning on appliances and easily determine how many watts each uses. When that's done just let the Emporia run for a few days while you go about your normal routine. Then view the data for Min, Hr, Day and will have a better idea how to size your solar system.
If want data from some of the individual branch breakers by all means get the 8 or 16 CT version if you don't mind spending a little more.

Great thank you for your help. This is my next step