Solar Power Research Fall 2023

Selecting a solar setup that largely depends on both your budget and the power needs of things you want to run on AC or DC power. After doing some basic homework it is readily apparent that going “in the deep end” and looking to power an entire home or even charge up a Tesla is going to be big expensive learning curve. I started with an entry-level system and now, at the 3,000 W (3 kW) range and jumping right into the “big league”.

Time to break things down not just by solar components, but by size of the project. Before getting into that let’s first talk about the primary components of the system. Most of the components need to be scaled up based on the size of the system. How quickly things need to be changed to the “next size up” largely depends on the components.

Primary Solar System Components

I am going to talk about the primary power generation, storage, and transfer components. Other components like the mounting systems, tracking systems, and other related items that may be part of a full solar installation are not part of this discussion. Those elements largely depend on the type of installation you are planning (roof or ground?) and how “techie” you want to get — solar tracking, passive solar, or latitude/season manual adjustment. For the purpose of this part of the discussion we are talking about only the things that make, store, and transfer power.

Also keep in mind I am not a solar industry expert, only a “Joe property owner” figure shit out, making mistakes, and reading a lot of (probably wrong) stuff on the Internet.

Primary Solar System Components

• Panels – generate the power.
  Rated in watts , usually output 12v nominal — but that varies some based on shading etc. Typically the higher the watts generate the more they cost. Sometimes they are larger in size but not by a lot. Most now have an integrated MC4 style “plug and play” DC power connector color coded in red and black. In my experience the actual output tends to come in at about 50% of what they market the panel at. Figure a 100W panel will generate 50W per hour (50Wh) on a good day. Many days are not “good days” for solar generation.
  
• Charge Controller – manages how much power to push into the batteries. The solar output is highly variable and while it may output a nominal 12v or so (usually a bit closer to 14) the amps varies significantly. The charge controller takes that power and figures out how to get it to push hard enough to get the energy into a battery for storage — or keep the energy from “leaking out” if there is not enough power coming from the panels.
  
• Batteries – store the power. Often rated in volts (usually 12v for basic systems, but you can find 24v and 48v as well) and most now list Amp Hours (aH) which is essentially the “size of the tank”. A 100Ah 12V battery stores 5x as much power as a 20Ah 12V battery.
  
• Inverter – an optional component that converts DC power , like that from solar panels and batteries to AC power. In the United States that means we almost always want typical 110V “American style” power outlets on the unit. Many of these , especially larger units, also have an LNG terminal — which is basically the positive, neutral, and ground lugs that you can screw on normal 3-wire house wire to. Good for wiring up standard outlets, lites, etc. that we are all used to. Inverters are optional, but convenient.
  
• Wiring – there are a few different wire types in involved:
  • Panel to Panel : MC4 connectors male-to-female on each end make this easy to wire in series or to a parallel “joiner”.
  • Panel to Charge Controller : an MC4 to controller (bare wire) adapter (Renogy RNG-AK)
  • Charge Controller to Battery : a bare wire to M8 lug (Renogy RNG-TRAYCB)
  • Batter to Inverter : an M8 to bare wire (usually included with the inverter — same as above charger controller to battery)

Large Project: Solar Powered Tesla Model S

A notebook on solar power for a Tesla Model S.

Model: ’16 P90D
Average Monthly Consumption: 360kWh
Average Daily Consumption (30d): 12kWh / day via destination charger 38A 220V

Gen 1 Mobile Adapter, Max 40A, 2.7 – 3.7 kW average, can max at 11 kW with proper adapter
NEMA 14-50 : 50A “Appliance Plug”, 240V 50A charges at 38A on average = about 40 miles of range per hour of charging.
TT30 Adapter (TES1-1575) : 30A 120V RV Service Plug, charges at 20A = about 15 miles of range per hour of charging
NEMA 5-15 : 15A “120 Outlet”, charges at 7-10A depending on heat generation on circuit = about 7 miles range per hour of charging.

Component Calculations

Panels

A 1.5 kW system over 8h of daylight should generate about (8h * 1.5 kW) = 12kWh per day.
At a 50% typical generation the 1760W Sonali system would generate 880W * 8h = 7kWh per day

(4) Sonali SS-M-440 : $1,611

Charge Controller

Charge Current: 60A 4x 440W panels in a 4-up wiring falls under the 3200W @48V.

(1) Renogy 60A : $290

Batteries

For a 3000W inverter you need at least 300Ah of battery storage to keep the system running.
(3) x Renogy ‎RNG-BATT-AGM12-100 @ $190 = $570

M8 is a typical connector for batteries, an 8mm female connector.

Inverter

TT30 Adapter charges at 20A, 20A * 120V = 2400W which means you will want a 3000W inverter at a minimum.
(1) Renogy 3000W 12V Pure Sine Wave Inverter : $380 + shipping

Wiring

Wiring from the inverter will need to be to an inverter with an LGN connection, 240V preferred, 120V is OK. Support for a 30A circuit is also preferred, which requires 10AWG (30A). If you run only 15A a 14AWG will suffice.

Research & Pricing of Components

Panels

Renogy	RSP200D-US	200W	200W @ 12v, Monocrystalline, 13 AWG 2.6′ Open: 23V / Optimum 19.2V @ 10.42A 58.7″ x 27.5″ x 1.38″ = 1614.25 sq in. = 8.07125 sqin/w	$239 at Renogy $1.195 / W
Renogy	RNG-100D-SS-US	100W	100W @ 12v, Mono, 14AWG 1.9′ Open: 24.3V / Opt 20.4V @ 4.91A 41.8″ x 20.9″ x 1.38″ = 873.62 sqin = 8.7362 sqin / w	$85 at Amazon (6 days) $90 at Renogy $1.03 / w
Renogy		550W	550w panels x4 = 2200 w	$1670 at Renogy $312 shipping $141 tax $2152 = $0.97 / w
Canadian Solar	TOPHiKu6 : CS6W-585T	585W	585W Open 52.4V / Opt 43.3V @ 13.52A 89.7″ x 44.6″ x 1.18″ = 4,000.62 sqin = 6.8387 sqin / w
Sonali	SS-M-440	440W	440W Open 41.2V / Opt. 34.5V @ 12.74A 75.2″ x 44.65″ x 1.38″ = 3,357.68 sqin = 7.631 sqin/W 1760w for 4	$196 US Solar Supplier $143 shipping $84 tax $1010 = $0.58 / w $240 at Solar Panel Store (min 4) $0.55 / w + $661 shipping $1,611 delivered = $0.92 / w
Expert Power	SPERM410	410W	410W Open 37.12V / Max 3.35V @ 13.08A 67.9″ x 44.7″ x 1.4″ = 7.40 sqin / W	$1240 at Expert Power (4 panels included) $0.75 / w + $400 shipping + $115 taxes $1755 delivered = $1.08 / w

Charge Controllers

Charge controllers take the PV input and put it into a form the batteries can use.
MPPT : Maximum Power Point Tracking : tracks solar output current and voltage and auto-adjusts to maximize power, especially in low light.
PWM : Pulse Width Modulation : less efficient but lower cost
Many controllers have a load connection to allow direct connection of any 12V DC device to the controller.
Some controllers have a 5V DC USB connection as well.

In our starter kit we got an Expert Power 10A PWM charger controller. Charge current rated at 20A, with 55V PV max input voltage.

We are running (2) 100W 12V panels wired in series = 100W @ 24V = 4.16A max output.

The controllers listed here are all MPPT.

Renogy	Rover Li 40A RNG-CTRL-RVR40-US	40A	520W @ 12V 1040W @ 24V	Includes battery temp sensor Option: BT-1 Bluetooth module	$160 at Renogy $139 at Amazon (2 days)
Renogy	Rover 60a RNG-CTRL-RVR60	60a	800W @ 12V 1600W @ 24V 2400W @ 36V 3200W @48V Load: 20A	Remote battery temp sensor Option: BT-1 Bluetooth module Option: DM1 4G cell module	$299 at Renogy
Renogy	Rover 100A RNG-CTRL-RVR100/RNG-CTRL-RVR100	100A	1300W/12V 2600W/24V 3900W/36V 5200W/48V		$660 at Renogy

Batteries

LiFEPO4 charges faster than AGM, discharge more deeply (80% vs. 50% recommended max discharge), have more charge cycles, and longer lifespan (10y vs 3-5y).

Size the battery based on the load. This is simply the amps being drawn by the load * hours to be run. Most appliances list watts and volts. A 100W appliance running at 120V = 100W / 120V = 0.83 A. One hour of using this appliance will need about 0.9 Ah of battery storage.

The batteries listed here are all 12 volt with M8 terminals.

AGM		Storage (Ah)
Renogy	RNG-BATT-AGM12-100	100	13.1 x 6.9 x 8.6 in 332 x 175 x 219 mm 63.9 lbs 29 kg	$190 at Amazon (7 days) $190 at Home Depot (12 days)
Weize	‎QS12-100-T	100	12.99x 6.73x 8.43 in 63 lbs	$156 at Amazon (2 days)
Renogy	RNG-BATT-AGM12-200-US	200		$370 at Renogy $1.85 / Ah
Mighty Max	ML4D	200	20.87″ x 9.45″ x 8.74″	$360 at Amazon
Expert Power	EXP200-GEL SKU: BGHFM12_200	200	20.55″ x 9.4″ x 8.54″ 1Y Warranty	$400 at Expert Power
LiFePO4
LiTime	Model: LT-200 MPN: AP-200	200	21″ x 8.5″ x 8.2″ 45.8 lbs	$490 at Amazon
Expert Power	EP12200	200	20.6″ x 9.5″ x 8.8″ 48.3 lbs	$600 at Expert Power

Inverters

Connect directly to the battery bank and convert DC stored energy to AC output.

Inverter Only		Output (W)
Renogy	1000W 12V Pure Sine Wave Inverter RNG-INVT-1000-12V-P2-US	1000	(2) 115V AC (1) USB 5V 2.1A LGN AC Block Input 12V / M8	Refmote AC 19.8ft On/Off Switch 4AWG Cable 3ft	$170 at Amazon (7 days) $190 at Renogy $190 at Home Depot (12 days)
Renogy	2000W 12V Inverter	2000	(3) 115AC (1) USB 5V 2.1A Input 12V / M8	Remote AC 16.4ft On/Off Switch 1/0AWG Cable 3ft	$260 at Amazon (2 days)
Renogy	3000W 12V Pure Sine Wave Inverter	3000	(3) 15A outlets 120V 1x LNG AC Direct Wire Block 1x USB-A 5V 2.1A Input: 12V / M8	Remote AC On/Off Switch	$380 at Renogy
Inverter/Controller		Output (W) / Charge Current (A)
Expert Power		2000 / 40	98% efficiency	Grid Power Charging option
Renogy	3500W 48V Pure Sine Wave Inverter/Charger	3500 / 80	48v / 3500w 80A \ 145v MPPT requires 48v battery bank		$570 at Amazon