Grape Solar Preconfigured Kits User Guide
- June 7, 2024
- Grape Solar
Table of Contents
- Overview
- System Sizing: Step 1 Determine Consumption
- System Sizing: Step 2 Calculate Panel Count
- System Sizing: Step 3 Inverter Sizing
- System Sizing: Step 4 Battery Bank Sizing
- Mounting Hardware & Additional Accessories
- References
- Read User Manual Online (PDF format)
- Download This Manual (PDF format)
http://www.grapesolar.com/index.php/products/modulesandkits/gs100kit/
GS – 100+ KIT EXPANDABLE PHOTOVOLTAIC POWER GENERATION SYSTEM
Kit Sizing Guide Rev. 170615
GS-100+ Preconfigured Kits
Kit Sizing Guide
©Copyright 2012, Grape Solar, Inc. All Rights Reserved
Overview
The GS-100+Preconfigured Kits are designed to be modular and expandable solar
generators, capable of meeting a wide variety of power production needs. This
kit can be as simple as a battery charger or expanded to provide enough power
to continuously support a cabin. With everything you need and nothing you
don’t need, these kits are the most cost-effective of their kind.
Grape Solar understands that one size does not fit all when it comes to solar
power and that power consumption tends to grow over time. With the
GS-100+Preconfigured Kits you will be able to meet your power generation goals
in a system that can cost-effectively grow with your changing needs.
System Sizing: Step 1 Determine Consumption
To determine the total system size you must first calculate your consumption in Watt-hours (Wh) per day.
Lighting
If you have four 15W LED lights (actual wattage not equivalent wattage) that
you plan on running for 8 hours per day, you would take the wattage of each
bulb, multiply it by the number of bulbs and multiply that by the number of
hours of run time per day.
4 bulbs x 15 W/bulb x 8 hours/day = 480 Wh/day
Pumps and Motors
If you plan to run a 1 horsepower (hp) pump for 1/2 hour per day you would
first convert the hp into Watts: 1hp = 745W, Then multiply that by a number of
hours of run time per day.
1 pump x 745 W/pump x 0.5 hours/day = 373 Wh/day
Misc. Electronics
If you want a system to power your laptop for 6 hours per day plus a microwave
oven for 10 minutes per day you would first need to determine the wattage of
each device. This information can usually be found on the device or
approximated with the help of an internet search. Let’s assume that the laptop
consumes 65W and the microwave oven consumes 800W. Multiply each device’s
wattage by its run time and add the two numbers together.
1 laptop x 65 W/laptop x 6 hours/day = 390 Wh/day 1 oven x 800 W/oven x (10/60) hours/day = 134 Wh/day 390 Wh/day + 134 Wh/day = 523 Wh/day
Battery Charging
If your plan is to keep a battery bank charged, first add up the Amp-hour (Ah)
capacity of all the batteries in your system. The Ah capacity is usually shown
on the side of the battery. For example, an RV with two 80Ah would have a
160Ah battery bank. For this calculation, it doesn’t matter if the batteries
are connected in series or parallel. Most batteries can only discharge 50% of
their Ah capacity so only 50% of the total Ah rating needs to be fed to them
to bring them to full charge. In this case that would be 160 divided by two,
equaling 80Ah. To convert Ah into Watt-hours, multiply 80Ah by 12V.
2 batteries/day x 80 Ah/battery x 0.50 x 12 V = 960 Wh/day
Watts vs. Watt hours
Keep in mind that Watts is an instantaneous power measurement, not to be
confused with Watt-hours, which is the actual energy consumption. Watts must
be multiplied by estimated run time to determine energy consumption. A good
analogy would be speed vs. distance. Watts are equivalent to speed, whereas
Watt-hours would be the distance. In order to determine how many panels are
needed you need to know the “distance.”
System Sizing: Step 2 Calculate Panel Count
On an average day, a single 100W panel will produce about 300 Watt-hours (Wh) of charge. This figure will vary depending on temperature, brightness, and time of sun exposure. In the Summer production will be higher than in the Winter. On bright sunny days the output will be higher than on cloudy days.
A single 100W panel will have an average daily production of 300 Watt-hours (Wh) = 0.30 kiloWatt hours (kWh) = 25 Amp-hours (Ah)
After determining your consumption in step one, divide that number by the production of a single panel:
Lighting example: Four 15W LEDs for 8 hours per day
480 Wh / 300 Wh/panel = 1.6 panels = 2 panels
Pumps and Motors example: One 1hp pump for 1/2 hour per day
373 Wh / 300 Wh/panel = 1.24 panels = 2 panels
Misc. Electronics example: One 65W laptop for 6 hours and one 800W
microwave for 10 minutes, per day
523 Wh / 300 Wh/panel = 1.74 panels = 2 panels
Battery Charging example: Two 80Ah batteries per day
960 Wh / 300 Wh/panel = 3.2 panels = 4 panels
Area Specific Production: More accurate panel production estimates can be made by using an online program that takes into account the local climate, latitude, tilt angle and bearing of the panel.
The simulator can be found here: http://rredc.nrel.gov/solar/calculators/PVWATTS/version1
- Click on your State
- Click on the city nearest to your location
- Change the DC rating from 4.0 to 100 (to simulate a single 100W panel)*
- Change the tilt angle to whatever your panel is tilted at (ideal is equal to your latitude)
- Confirm that your azimuth is correct (180 degrees, facing South, is optimal)
- Click “Calculate”
A new page will show a “Results” box. The middle column “AC energy” will show
your panel output broken down per each month in Watt-hours. For example, the
total Watt hour for an optimally tilted panel for one year of production in
Eugene is 106,794Wh. The daily production would be 292Wh.
Please note: PV Watts deals in kW & kWh. If you typed 0.1kW to represent a 100W panel the program would round your input up to 4.0kW. To adjust for this, mentally substitute W for kW. Input your data in Watts (W = 1/1000 of a kW) and know that your output is in Wh, not kWh as shown on the website.
106,794 Wh/yr / 365 days/yr = 292 Wh/day
System Sizing: Step 3 Inverter Sizing
The solar panels put out DC power that is fed through a charge controller onto
a battery bank. If you have an application that requires AC power you will
need an inverter to take that power off of the battery and turn it into 120V
AC.
When selecting an inverter it is important to know the total Wattage of your load. In Step 1 we determined the Watt Hour consumption, but for inverter sizing we can go back to just using Watts, and ignore the time factor.
The GS-100+KIT has two options for inverters, a light 450W modified sine and a heavy 2000W pure sine. Because of the modular design of this kit, other inverters may be used as long as they are compatible with the voltage of the battery bank.
Lighting example: Four 15W LEDs for 8 hours per day
4 Bulbs x 15 W/bulb = 60 W Use the small 450 W inverter
Pumps and Motors example: One 1hp pump for 1/2 hour per day
1 pump x 745 W/pump = 745 W Use the larger 2000 W inverter
Misc. Electronics example: One 65W laptop for 6 hours and one 800W microwave for 10 minutes, per day
1 laptop x 65 W/laptop = 65 W Use the 450 W inverter
1 microwave x 800 W/microwave = 800 W Use the 2000 W inverter
Together = 65 W + 800 W = 865 W Use the 2000 W inverter
Battery Charging example: Two 80Ah batteries per day
No AC required – No inverter needed
Pure Sine vs. Modified Sine
The 450W inverter option uses what is called a modified sine wave. This means
that the output of the inverter looks more like a stair-step pattern than the
smooth wave shown in the diagram above. Modified Sine is fine for charging
small devices but if you plan to use anything that has an AC motor you will
need the 2000W inverter with pure sine output. Also, some stereos and musical
equipment may emit an unwanted “hum” when powered by a modified sine inverter.
System Sizing: Step 4 Battery Bank Sizing
The GS-100+ Preconfigured Kits do not come with batteries but will work with
most deep cycle batteries. A deep cycle battery is designed to be charged and
discharged regularly, unlike standard car batteries that are meant to hold a
somewhat constant charge. Deep cycle batteries come in many forms including
lead-acid, sealed AGM, and Lithium-Ion. A typical deep cycle battery can
discharge about 50% of it’s Amp hour (Ah) capacity.
If you need a battery to store 1200Wh of charge you first need to convert the
1200Wh to Ah by dividing it by 12V (the voltage of a battery) to get 100Ah.
Since the battery can only discharge 50% of it’s capacity, you must divide the
100Ah by 50% to get 200Ah. A 200Ah battery bank will store 1200Wh of usable
power.
1200 Wh / 12 V = 100 Ah 100 Ah / 0.50 = 200 Ah battery bank
Lighting example: Four 15W LEDs for 8 hours per day, one day back-up
480 Wh / 12 V = 40 Ah (40 Ah / 0.50) x 1 day = 80 Ah battery bank
Pumps and Motors example: One 1hp pump for 1/2 hour per day, three day
back-up
373 Wh / 12 V = 31 Ah (31 Ah / 0.50) x 3 days = 187 Ah battery bank
Misc. Electronics example: One 65W laptop for 6 hours and one 800W microwave for 10 minutes, one week back-up
523 Wh / 12 V = 44 Ah (44 Ah / 0.50) x 7 days = 616 Ah battery bank
Battery Connections: Multiple batteries can be connected to each system.
Since the charge controller and 100+KIT are de-signed for 12V systems it is
12V batteries are connected in parallel and if incorporates 6V batteries they
should be pairs. other to increase the Amp Hour storage capacity of your
inverters in the GSimportant that multiple your system connected in series
Battery Life:
Batteries have a limited life. A battery that is discharged 50% every day will
not last as long as a battery that is only discharged 20% every day. Consider
this when designing your system, adding “too many” batteries will not
adversely affect the electrical performance of your kit but it will increase
the life of all the batteries in the system.
Connecting Panels in Parallel
The solar panel comes with 900mm MC4 leads, one for positive (+) and the other
for negative (-). The connectors plug into the MC4 leads for the Charge
Controller, or in multiple panel systems, plug into the MC4 T Branch
connectors. Panels can be connected in parallel (+ to + and – to -), but never
connect panels in series because this may result in a voltage that is too high
for the charge controller. Below are some diagrams showing parallel
connections:
Additional MC4 cables and connectors can be found in well-stocked electrical
supply warehouses or on Amazon.com by searching the term “MC4”
Mounting Hardware & Additional Accessories
Mounting Because of the wide variety of possible user applications, Grape Solar panels do not come standard with mounting hardware, but the panels come with sturdy aluminum frames that have mounting holes and can be mounted to a variety of structures and materials including wooden or metal frames.
For optimum energy production, solar panels should be pointed in the direction
of the sun to maximize the surface area that can receive light. Since the sun
is a moving target, this is best approximated by pointing the panel to the
South (for those of us that live in the Northern hemisphere) at a tilt angle
equal to your latitude.
If you plan to mount your panel to an RV, boat, or other vehicle Grape Solar
Technical Support can recommend some quality products. Call Grape Solar
Technical Support at
1-877-264-1014.
Breakers and Fuses
The GS-100+KIT is designed to include only the basic components needed for
operation. In low voltage photovoltaic systems, the likelihood of a power
surge damaging your equipment is nearly nonexistent, therefore breakers and
fuses are not included. But, that doesn’t mean that correctly sized breakers
and fuses will harm the performance of your system. Breakers or fuses can be
added between the panels and the charge controller (10A per every panel),
between the charge controller and the battery bank (60A) and between the
battery and inverter (250A).
Grounding
Grape Solar off-grid panels have grounding holes on the panel frame. Please
refer to the Safety and Installation Manual included with the panel. We
recommend 12 gauge wire for grounding. Inverters and charge controllers should
be grounded according to the manufacturer’s instructions.
Common Questions
How many batteries will I need to go with my panels? Batteries have to do with
how much power storage your system needs regardless of how much generation
capacity you have. You can have 10kW of solar panels charging a 36Ah battery
or you could have one 100W panel charging 1200Ah of batteries. The panel just
affects how quickly the battery can be charged. If the battery bank is fully
charged the charge controller will prevent overcharging.
What inverters will work with my panels?
In an off-grid, battery backup system, the inverter is connected to a battery
bank and the panels feed power onto the battery bank through a charge
controller. Since the inverter isn’t directly connected to the panels, you can
use any size inverter you want as long as it is compatible with your battery
bank and the devices you plan to power. You can have 10kW of solar panels in
the same system as a 450W inverter or you could have one 100W panel in the
same system as a 7kW inverter. The size of the inverter just limits the size
of the devices that your system can power, which affects how quickly the
battery bank is drained. Inverter size has nothing to do with panel count.
Are these 12V or 24V panels?
Panel voltage varies depending on temperature and brightness and load. The
typical operating voltage of these panels is 18.5V. If the panel was exactly
12V there wouldn’t be a large enough differential between the panels and the
battery for current to flow from the panel to the battery. If you find panels
advertised as “12V” they likely aren’t actually 12V panels. If they were 12V
panels you wouldn’t want them for charging 12V batteries because they wouldn’t
work. The charge controller changes the output of the panel from the 18.5V to
around 13.5V that would be fed onto the battery.
If the charge controller is lowering the voltage, am I losing power?
Power equals voltage multiplied by current (amps). When the charge controller
lowers the voltage it increases the current, like a transformer.
My equipment is connected correctly but I’m barely getting any current,
why?
Check the voltage of your battery bank. If it is over 13V the charge
controller may be reducing the flow to prevent overcharging the battery. This
means your system is working perfectly. If the battery voltage is low, the
battery may be damaged. If the problem persists, contact Grape Solar customer
support.
www.grapesolar.com
Tel. 1-877-264-1014 (toll free),
1-541-349-9000,
Fax: 1-541-343-9000
Valid from March 2014
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>