Newbie ready to join the solar crowd, maybe...

[Southerntester]

I just joined the forum and have been reading so much great info and trying to absorb as much as possible. My hope is to squeeze in a diy solar system purchase before the death of the tax credit. I live in the Shenandoah Valley of Virginia and our rate is effectively $0.15 and I believe the coop has 1-1 net metering. Before I started reading on this forum the plan was a scalable grid tie system, hoping to stay as inexpensive as possible right now but expand when we can. Now I'm thinking maybe not a grid tie system but a stand alone with batteries? My goal is to save money, period. I don't really have a budget in mind and we have plenty of open space to place an array. I've attached the electric usage history, hopefully that's a good starting point. My service is 400amp with 2 Siemens 200amp panels, located in my unfinished basement. I am not a master electrician but I have many years of electrical experience and am planning to DIY this project even though I am a complete novice when it comes to solar. We don't loose grid power very often and almost never for very long so the batteries would be for cost savings overnight but not at all opposed to eventually being completely off grid, assuming we can keep all our modern conveniences.

I'm looking for recommendations for a scalable system. Should I grid tie or stand alone? What's a good jumping in price point with expansion in mind. Hopefully I've provided enough information to get the conversation started.

Matthew

 

[kc130up]

Welcome to the club! You are in the right place for DIY solar.

The combined usage for a month is a great start. Do you have any daily or hourly stats?

We'd also need to know what your max current draw is to make sure your equipment can safely handle the instant demand.

Is that 3MW in august?

Saving money is easy - the question is how much? Are you looking to cut electric consumption by 25, 50, 75, 100%?

Once those questions are answered, we can talk what's required to hit that target!

 

[Southerntester]

Welcome to the club! You are in the right place for DIY solar.

The combined usage for a month is a great start. Do you have any daily or hourly stats?

We'd also need to know what your max current draw is to make sure your equipment can safely handle the instant demand.

Is that 3MW in august?

Saving money is easy - the question is how much? Are you looking to cut electric consumption by 25, 50, 75, 100%?

Once those questions are answered, we can talk what's required to hit that target!

Hourly peak for the highest day in August was 14.

Not sure about max draw, we have a geothermal AC, 80 gallon electric water heater and standard electric dryer.

I believe the total for August was 3045kwh, so yep it was.

I'd like to start at saving 50% and eventually build to somewhere closer too 100%.

I just watched a couple of Will's videos and one of them talked about separating loads and building an off grid setup for just certain loads. That sound like it might be a place for me to start, building a system that isn't grid tied and avoiding the hassle. Does that make sense? What loads would make sense to focus on?

I know it's last minute but I'm trying to squeeze all this in before the tax credits expire. Just don't wanna waste money to save a little.

Thanks





sounds like a place I might want to start. Does that make sense, avoiding the hassle of a grid tie system? Of my major draws mentioned above, wh

 

[kc130up]

Grid tied is only a hassle if permits and doing things that will pass electrical inspection is something to avoid. Grid tie can be a "waste of time" if your utility company has a crappy net metering plan. I would research your area's net metering plan to determine if its worth while.

You can also build a system that can do both and a system that you can scale later, but its a bigger up front investment. The possibilities are endless. Determine what is important so we can row in that direction.

While you ponder grid/off-grid, you'll still need enough panels to achieve your 50% goal.

Without doing all the math from the chart, I estimate your average monthly is ~ 1500kWh. 50% of that is 750kWh a month which is 25kWh a day.
We get about 4 hours of sun per day up north on the east coast, so you'll need to produce 6.25kWh an hour to get to 50% reduction.

There are also cloudy and rain days, so I would bump that up ~ 20% to 7.5kWh of needed hourly production.

Now I leave you with some homework. Check online for panels that are available and within your budget. Look at the nominal power (NMOT)

All spec sheets will list the nominal power, it is usually 25% of the "advertised" or STC power.


calculate the number of panels needed to get 7.5kWh an hour of nominal power.

Let me know what you find!

 

[Southerntester]

I got a quote from Signature solar for Bluesun 460w bifacial panels at about $160 per.

23 panels should get me to the 7.5kwh you mentioned using the NWOT

Looks like the panels aren't the bulk of the cost. The FlexBoss21 is what was recommended at roughly $6k, the rack system from Integra is $189 per section for the adjustable version. The power station fixed ground mount is less expensive and looks nice, I've been looking around at them as well.

Then come the batteries, wow.

I need to pick a direction and work towards that, just not certain yet. Grid tie vs off grid and batteries or not.

Thank you

 

[SnickeringBear]

I estimate your average monthly is ~ 1500kWh

Would be a better choice to start off at 2000 kWh consumed/month and target 1000 kWh toward that goal. Why? It takes into account the high usage months in summer and the low producing months of winter.

The simplest and fastest option is to put in a non-grid tied system using hybrid inverters. Rough estimate is that you need 24 kw of inverter capacity which can be supplied by 2 inverters each rated 12 kw. Sizing in a system based on this, you have about 260 days of effective solar production per year and would need a minimum of 60 kWh of battery storage. While your numbers for solar panels are reasonable, if you want to produce meaningful amounts of electricity in winter, you will need more panels. Bump it up to 40 and you will be in the ballpark of what will work.

Here are some suggestions. SRNE HEBP 12 kw hybrid inverters are about $2000 each currently so $4000 for two of them. Solar panels can be sourced a tad cheaper if you are willing to make a trip. https://jaysenergy.wixsite.com/jaysenergy sells 640 watt panels for about $179 each and he will cut the price some if you buy 30 or more of them. Batteries can be sourced from Docan Power in Houston for $2500 each plus shipping for 32 kWh batteries. Be careful, if you need UL listed batteries to meet local code, you will have to pay more from a different vendor. Also, don't mess with 5 kWh batteries. For your purposes, 15 or 32 kWh are the only size worth considering.

If an economy route is needed, get 1 inverter at 12 kw, 25 kw of solar panels, and 1 battery at 32 kWh.

 

[Brucey]

Would be a better choice to start off at 2000 kWh consumed/month and target 1000 kWh toward that goal. Why? It takes into account the high usage months in summer and the low producing months of winter.

The simplest and fastest option is to put in a non-grid tied system using hybrid inverters. Rough estimate is that you need 24 kw of inverter capacity which can be supplied by 2 inverters each rated 12 kw. Sizing in a system based on this, you have about 260 days of effective solar production per year and would need a minimum of 60 kWh of battery storage. While your numbers for solar panels are reasonable, if you want to produce meaningful amounts of electricity in winter, you will need more panels. Bump it up to 40 and you will be in the ballpark of what will work.

Here are some suggestions. SRNE HEBP 12 kw hybrid inverters are about $2000 each currently so $4000 for two of them. Solar panels can be sourced a tad cheaper if you are willing to make a trip. https://jaysenergy.wixsite.com/jaysenergy sells 640 watt panels for about $179 each and he will cut the price some if you buy 30 or more of them. Batteries can be sourced from Docan Power in Houston for $2500 each plus shipping for 32 kWh batteries. Be careful, if you need UL listed batteries to meet local code, you will have to pay more from a different vendor. Also, don't mess with 5 kWh batteries. For your purposes, 15 or 32 kWh are the only size worth considering.

If an economy route is needed, get 1 inverter at 12 kw, 25 kw of solar panels, and 1 battery at 32 kWh.

A single docan panda 32kWh is not a good choice for a 12kW inverter that needs 250A of battery BMS.

Its rated for regular charge/discharge rate of just 100A....even with two you'd be marginal.

Downside of very large batteries like this. Need several if your loads are significant.

 

[kc130up]

I got a quote from Signature solar for Bluesun 460w bifacial panels at about $160 per.

23 panels should get me to the 7.5kwh you mentioned using the NWOT

Looks like the panels aren't the bulk of the cost. The FlexBoss21 is what was recommended at roughly $6k, the rack system from Integra is $189 per section for the adjustable version. The power station fixed ground mount is less expensive and looks nice, I've been looking around at them as well.

Then come the batteries, wow.

I need to pick a direction and work towards that, just not certain yet. Grid tie vs off grid and batteries or not.

Thank you

The panels are indeed the cheapest part of the system.

A single FB21 is a good start if you're going grid tie. If a later goal is closer to 100% offset, start with a gridboss as you'll need atleast 1 more inverter and a GB making connecting them easy and cheap.

If doing off-grid, then the inverter options change!

As you discovered, the separate costs add up fast. With off grid, the biggest costs becomes batteries. With grid tie, the grid becomes the battery!

Lots to consider, it took me a few months and HOURS of research to settle on my plan.

We'll be here when you've settled on a direction!

 

[Southerntester]

I am so lost, gonna take a lot more reading to get me anywhere close.

Really thought I would order a plug and play complete setup, learn as I go installing it. Just had no idea there were so many choices on the front end.

Back to the forums for more reading...

 

[1201]

If you have net metering 1-1, just get a grid tie system and forget batteries completely.

Grid tie 11.4 kw growatt inverter is $1800 .
Get about 15kw of PV and you're done.

Don't complicate anything

 

[kc130up]

I am so lost, gonna take a lot more reading to get me anywhere close.

Really thought I would order a plug and play complete setup, learn as I go installing it. Just had no idea there were so many choices on the front end.

Back to the forums for more reading...

It gets simple ONCE the decision of grid/off-grid is made. When looking at both options, its a lot at once!

 

[Southerntester]

After watching Wills video -

- I started a list with pricing



10KW 48V Split Phase Solar Inverter sungold power $2,225
16KWH battery https://yixiangpower.com $1,869
pv disconnect Amazon $27
power distribution box Amazon $81
BlueSun 460W solar panels Signature solar $5,000
IntegraRack IR-30 Signature solar $3,000
wire, cables & connectors various sources $1,000

Total $13,202

The prices from Signature Solar roughly include shipping. I know that is not a complete list, still need conduit etc...

My bill averages $300 a month, $3600 a year for electricity. This system won't completely eliminate my bill but should reduce it greatly?

I didn't include the 30% from Uncle Sam. That would drop the total to $9242 and reduce the payback to under 3 years.

Are there better options for an off grid system? Are these numbers good enough to make it make sense?

 

[SnickeringBear]

The inverter is a renamed SRNE 10 kw. You can purchase a 12 kw SRNE HEBP hybrid inverter for a tad under $2000. Ask where and someone will give you a link to the place that has them in stock in California.

 

[Southerntester]

Yes please, where can I find the 12kw inverter SnickeringBear mentioned...

 

[kc130up]

Solid choices. That list will put a dent in your bill. Even more of a dent some summertime!

Add a "misc." $1K to the budget for the unknowns

 

[1201]

After watching Wills video -

- I started a list with pricing



10KW 48V Split Phase Solar Inverter sungold power $2,225
16KWH battery https://yixiangpower.com $1,869
pv disconnect Amazon $27
power distribution box Amazon $81
BlueSun 460W solar panels Signature solar $5,000
IntegraRack IR-30 Signature solar $3,000
wire, cables & connectors various sources $1,000

Total $13,202

The prices from Signature Solar roughly include shipping. I know that is not a complete list, still need conduit etc...

My bill averages $300 a month, $3600 a year for electricity. This system won't completely eliminate my bill but should reduce it greatly?

I didn't include the 30% from Uncle Sam. That would drop the total to $9242 and reduce the payback to under 3 years.

Are there better options for an off grid system? Are these numbers good enough to make it make sense?

This is all the way wrong if your goal is to save money.

 

[SnickeringBear]

Read this thread. https://diysolarforum.com/threads/s...o-hybrid-with-200amp-passthrough-deal.108924/

 

[Southerntester]

1201, please expand. Which way should I go to meet my goal of saving money? I'm brand new and eager for input.

The PVWatts calculator says I'll get 14kwh+ a year from my 10k array.

All in right now we pay $0.15 per kwh and with quick math would save us $2100 a year.

Assuming our system cost is $15k, minus the tax rebate 30%, final cost would be $10,500.

Our break even point would be 5 years. Right?

 

[1201]

1201, please expand. Which way should I go to meet my goal of saving money? I'm brand new and eager for input.

The PVWatts calculator says I'll get 14kwh+ a year from my 10k array.

All in right now we pay $0.15 per kwh and with quick math would save us $2100 a year.

Assuming our system cost is $15k, minus the tax rebate 30%, final cost would be $10,500.

Our break even point would be 5 years. Right?

If you have 1:1 net metering you don't need an off-grid inverter or batteries.

The inverter in the vid does not export excess to the grid, and you would need a critical loads panel and have to move selected loads to the clp, which means you would likely give up some solar production, and even the production you do have will not support all your house loads.

Batteries will save you zero money. Actually the batteries would cost you money since there are some losses in charging and discharging the battery.

Get a grid tie inverter for about $1600. By not buying a battery, battery cables, clp, and a more expensive inverter you are probably saving $3000 which means your payback is that much faster.

By being interconnected to the grid your get to use the grid as your battery, sell all your excess production, support ALL your house loads, and achieve maximum efficiency.

 

[SnickeringBear]

How to plan for a solar power home or small business system

There are a few critical numbers which determine hardware requirements to support a solar power plant plus some additional questions that determine the way it is configured.

1. How many kWh per year will this location use? (determines solar panel capacity) If this is a newly built location, the number of kWh/year can be estimated by calculating how much power each connected load needs. Power bills for the past year are the fastest way to find this number. Once you have this number, kw of solar panels will be easily determined.

2. How many kWh are consumed on the highest day of the year? (determines how much battery storage is needed) My home is fairly low at 30 kWh consumed on the highest day in the past year. So how do you figure battery capacity required? Start with the same kWh of battery as kWh consumed on the highest day of the year. Since mine is 30 kWh consumed, I should install at least 30 kWh of battery storage. This will cover 1 full day of usage in inclement weather. If I want 2 days of backup, double the daily usage. In my case, that would be 60 kWh of battery storage.

3. How many kWh are consumed in the peak hour of usage? (determines inverter capacity)

4. Do you either own an EV or plan to purchase one in the next few years? (must add panels, battery, and inverter capacity) There are several valid strategies for charging an EV. The first is to sign up for a Time Of Use plan with the local utility provider. Charge the EV at whatever time is lowest cost. This is usually late at night into early moring. If self-powered charging is required, determine when the EV will be charged. If during the day when power is being produced, all that is needed is to size the panels and inverter large enough to cover EV requirements. If charging will be mostly at night, then enough stationary battery capacity should be provided to cover charging the EV.

5. Is some form of NEM (Net Energy Metering) available at this location? If yes, find out if it is 1:1 where a kWh sent to the grid can be drawn from the grid at no added cost. If NEM 1:1 is not available, it is best to plan for batteries to store excess power.

6. Generator backup should be considered if having power in an outage is a concern. A rule of thumb is that most homes can get by with about 9 kw of generator capacity.

Your basic list of hardware for a standalone system with batteries should include:

1. A transfer switch or alternatively gridboss or similar with built in disconnect when the grid is down
2. Inverter capacity, preferably highly redundant so that failure of an inverter does not stop the show
3. Solar panels sufficient to produce power to run critical loads at minimum and entire house if desired
4. Mounting hardware for solar panels, breaker panel with circuit breakers, cables, and miscellaneous
5. Battery capacity to support your home through at least 1 full day of normal operation

Gotchas to watch for are not having enough MPPT capacity to interface the panels you need. As an example, if you want 25 kw of solar panels and your MPPT's can only interface 20 kw, you have a problem. Check the capacity of the inverter/MPPT's to ensure they will match with your kw of panels. Another gotcha is purchasing overpriced equipment before you know enough to make an intelligent decision.

As a heads up, SRNE HEBP 12 kw hybrid 240V inverters have dual 9000 watt MPPT's. This is generally enough for most homes.

 

[SnickeringBear]

An early decision has to be made whether or not to grid-tie the solar hardware. If yes, then permits have to be issued by regulatory authorities and the grid operator has to give approval to the overall plan. Most will need engineering support to get through this process.

Deciding whether or not to install batteries is determined by whether or not you already have a house generator. If yes, batteries are less likely to add value. It is also determined by whether or not the grid operator offers 1:1 net metering. If yes, batteries probably are not needed... unless you are in an area subject to frequent grid outages in which case batteries for power during an outage can literally save your bacon (by keeping the refrigerator running).

Unexpected requirements can hit you with huge bills. An example is a requirement for a million dollar liability insurance policy which may cost a few thousand dollars a year. Yes, some utilities require such a policy. Another is when the transformer supplying your home has to be replaced to handle the power feed from solar. It can easily cost $10,000.

One huge hurdle to doing your own solar is the tools required for the job. A simple example is a hydraulic crimper to attach lugs on cables. You also should be fairly competent working on a roof. Did I mention I worked as a roofer one summer just out of high school? If you are not capable of walking on a roof safely, just DON'T!

Sometimes small bits of knowledge can trip you up when doing a solar install. Here is one tidbit that nearly got me. Inverters in the U.S. provide split 240V electricity. If you purchase a 5 kw split inverter, you get 2.5 kw on one leg and 2.5 kw on the other. Some inverters allow higher use on one side and some don't. Why is this a problem? Lets say you turn on the microwave and at the same time your wife tries to use her blow dryer. Between them, they draw 3 kw which means you have now exceeded the 2.5 kw available on one leg of your inverter. How do you avoid this problem? Connect the circuit for the microwave on one leg of inverter output and the blow dryer on the other. So how did this almost catch me? I set up my tiny house with 24 outlets plus half a dozen lights (I don't want to have to go far to plug into electricity) and used 4 breakers rated 20 amps to serve all of them. It was inherently impossible to guarantee that large loads would not show up on one leg from the inverter. How did I fix it? I split the outlets and lights into 9 separate circuits with no more than 4 outlets/lights on one circuit. This allows me to swap connections around in the breaker panel until everything is balanced. I will balance it when first turned on, but if something changes 5 years from now, it will be very simple to swap things around in the breaker panel. Fortunately, I had not yet finished the electrical wiring so can run a few extra power leads and change a few connections in outlets to make this work.

What about using micro-inverters? Micros are highly useful for grid tie systems where solar panels are compromised by roof shading and where grid tie with 1:1 net metering is available. They ensure each panel is capable of maximum output. Grid optimizers are available for DC systems but add expense and reduce efficiency a bit. If you are installing batteries, micro-inverters cause a problem because they convert DC from panels directly into AC 240V. Charging a battery requires that AC be turned back to DC when then has to be turned back into AC if you need to use the batteries. All the conversion steps reduce efficiency and increase cost. Ask people who installed AC coupled batteries how much they cost. By comparison, a DC coupled battery has solar panels connected to an MPPT (glorified battery charger) which directly feeds to the battery. The battery is connected to an inverter which turns DC into AC usable in the home.

What can you do if you want to install your own solar? Visit some of the solar DIY forums and ask questions. Post your proposed system and ask for feedback on installing it. Be prepared to get an engineer involved if grid-tie is part of your plan. It will cost some money but will pay for itself in the long run.

What is the most expensive mistake you can make? Other than burning your house down, purchasing the wrong equipment or too expensive equipment is near the top. This can be avoided by learning how to properly size solar for your specific location and needs. As an example, say your house uses 12,000 kWh per year from the grid. Most will average this to 1000 kWh/month which may be perfectly acceptable, particularly if you are grid tied on 1:1 net metering. But if you are off-grid and have to produce your own power year round including in winter when the sun is low in the sky and cloudy rainy days are common, I have this tiny violin you might want to learn to play. So what do you do?

12000 kWh needed in a year with 280 days of likely production suggests you need 12000/280 = 43 kWh of solar production on those days. If your area is likely to give 5 hours of production on each sunny day, 43/5 gives 8.6 kw of solar panels. If - and emphasize this - you are off-grid and need production on short cloudy winter days, double this number or a bit more to ensure you have enough electricity to keep the lights on. In my case, I'm installing 11.2 kw of solar panels with plans to add more if and when needed.

How do you size batteries? Figure out your daily kWh consumed. If you need 32 kWh for an average day, you probably want a buffer to cover another day or two just in case multiple cloudy days in a row impact production. I'm installing 60 kWh of batteries because my expected daily consumption is 15 kWh so I want 4 days of buffer.

What about inverters? Inverters have to be sized for 2 very specific requirements. The first is they have to be large enough to provide the instantaneous amount of power you consume on the highest hour of the year. Say your air conditioner is running at the same time you are cooking on the stove and washing and drying a couple of loads of clothes. As a power engineer, I immediately convert stove = 30 amps, air conditioner = 30 amps, washer = 3 amps, dryer = 20 amps for a total of 83 amps. A 12 kw inverter supplies 50 amps so you need two of them to cover the maximum power consumption when all these appliances are on at the same time.

What is the very first thing you should do if you are interested in installing solar? Start out by evaluating every appliance in your house and upgrade to something more efficient. The most common example of a power pig is a hot water heater whether tank or tankless. A heat pump water heater will use half as much electricity typically shaving power consumption by about 8 kWh/day for a family of 4. If you have gas appliances, consider ways to replace them with electric versions. Gas heater? A heat pump may be in your future. Gas cook stove? An electric stove might be a good option. Poorly insulated house with single pane windows? Add insulation and upgrade the windows to save kWh on heating and cooling. If your roof needs to be replaced, do this before attempting solar.

Don't forget a generator. If your battery is depleted, a generator can provide power to charge the battery and keep the lights on.

 

[SnickeringBear]

Well insulated house: Start with the house itself which should be insulated and tested for air penetration. It should be water tight and air tight so that heating and cooling are as efficient as feasible. This will reduce both size of heat pump and how much power it consumes. A heat pump that is highly efficient and is optimized to work efficiently at colder temperatures will be needed.

EV charger: The highest power consumer in a home is likely to be an EV charger. Typical daily consumption seems to be about 40 kWh. If the EV can be charged during the day when solar panels are producing, battery size for house power can be significantly smaller. I am anticipating a solar charger powered with 40 amps at 240 volts or 9600 watts. This will take about 5 hours to fully charge a car presuming 40 kWh is needed.

Heat pump water heater: An efficient water heater can significantly reduce daily power consumption. I currently have a 65 gallon heat pump water heater which uses 3 kWh per day when I am using it for showers, washing clothes, washing dishes, and general house cleaning. More people in the house will translate to higher power consumption given that each person will add to the total amount of hot water needed daily.

Clothes Dryer: After heating and cooling and hot water, a clothes dryer is one of the most power hungry appliances. A resistive element dryer consumes between 4 and 10 kWh per load of clothes dried where size load is a factor in power consumption. I've done a deep dive into heat pump clothes dryers over the last few days and found many options which will work in my specific circumstances. I am building a tiny house with space constraints on just about everything including washer and dryer so I am looking for a stackable washer/dryer combo that is less than 78 inches tall. Searching for "heat pump clothes dryer" at Home Depot, Lowes, or Menards gives very few options. I found a cheat code when I figured out that searching for "ventless clothes dryer" returns many more most of which are heat pump clothes dryers. Maytag, Whirlpool, Samsung, and several others are available at prices from roughly $1100 to $2500. I am currently considering a Whirlpool 7.4 cubic foot stackable heat pump dryer which lists for $1600. I was unable to find any significantly lower power consuming clothes washers so will pair the dryer with a stackable electric washer.

Cook Stove: An efficient cook stove is almost an oxymoron given that electric stoves are either resistive element or induction coil. Since I am a cast iron collector and have a plentiful supply of the goods needed to cook on an induction stove, that is the direction I am leaning.

Well pump: Since I am off grid and far from any source of water, I will have to drill a well. Well pumps in general are not heavy power users, but they are amenable to other methods of saving. I can easily source a well pump that runs on 48 volts. My current plan is to power the pump from the solar batteries via a 48 volt circuit breaker.

Refrigerator: The only thing I could find that helps with a refrigerator is having thick insulation. Larger refrigerators inherently have an advantage as the ratio of interior capacity to insulated shell helps. I have a large capacity refrigerator that should do the job though I could probably purchase a more efficient model today.

Freezer: An upright freezer gives similar concerns as a refrigerator. Thick insulation and relatively large capacity are objectives. I have not yet decided on a freezer.

Dishwasher: Dishwashers that use a heating element to dry the dishes are a problem. In some climates, heated drying is required. Fortunately, in my climate dishes dry in 2 hours or less sans heating. Most dishwashers today have an ECO mode which turns off the heating element. I expect the dishwasher to consume about 1 kWh per use.

Lighting: All lights will have LED bulbs. They are so ubiquitous now that it is hard to find old style tungsten element bulbs. I am including flood lights outside the house as there are times they are both needed and useful.

Computer monitor/television: I won't have an extra large screen but have designed the house to accommodate one that is up to 57 inches diagonal measure.

Microwave and Air Fryer: These don't use many kWh per day but when they are used, power consumption is a consideration. I have wired an outlet each specifically for a microwave and air fryer so they will always have enough power to cover the loads. Microwaves typically use 900 to 1500 watts while air fryers are between 1500 and 2000 watts. These outlets have home runs to the breaker box and are connected to 20 amp breakers giving 2400 watts of capacity.

Hair dryer, laptop computer, cell phone charger, internet router, and other small appliances usually don't consume enough power to make a difference. I am wiring the tiny house with about 24 total power outlets along with 7 light fixtures. I don't want to have to look far to find a place to plug something in for power!

A pool pump and/or pool heater would require major changes in my solar power setup. I don't have a pool so it is not an issue. I may wind up building a greenhouse in the future but for now it is not a consideration.

If your house is like mine with a full basement, you may need a dehumidifier to keep moisture levels down. Running a large dehumidifier will cost about 15 kWh per day. This is a very significant load when running solar power as your only power source.

 

[Brucey]

1201, please expand. Which way should I go to meet my goal of saving money? I'm brand new and eager for input.

The PVWatts calculator says I'll get 14kwh+ a year from my 10k array.

All in right now we pay $0.15 per kwh and with quick math would save us $2100 a year.

Assuming our system cost is $15k, minus the tax rebate 30%, final cost would be $10,500.

Our break even point would be 5 years. Right?

1201s grid-tie solution will leave you in the dark if the grid goes out. When the grid is the battery but not available....

After spending $10-15k its nice to have some kind of battery and inverter to ride through at least small grid outages, even if it may increase your time to payoff.

 

[1201]

1201s grid-tie solution will leave you in the dark if the grid goes out. When the grid is the battery but not available....

After spending $10-15k its nice to have some kind of battery and inverter to ride through at least small grid outages, even if it may increase your time to payoff.

I'm not seeing where op mentioned an unreliable grid, or having backup as a goal.

So, adding that to the mix is just confusing the op and complicating matters.

 

[Southerntester]

I hear loud and clear what y'all are saying... grid tie. We don't lose power very often at all and when it does go down it's not for long periods.

I'm not a good rule follower and don't like looking to others for approval for what I do but I absolutely understand the need for safety. My coop (SVEC) has a net metering agreement posted and it seems to be workable. Looks like I'm heading towards a grid tie system.

Do solar companies have Black Friday deals?

The 11.4 Growatt grid tie inverter for $1800 with the 15kw PV makes sense (thanks 1201).