Wavemakers Frequently Asked Questions about solar power

Contents

Will a solar panel supply electricity 24 hours a day?
What size solar panel do I need?
Charge controller?
inverter?
Possible problems?
Will solar energy work even on a cloudy/overcast day?
What about in winter? Will the panels still work?
Can equipment be used directly from solar panels?
How do I maintain my solar panels?
Problems with mounting a solar panel?
Calculating your solar panel needs
Appliance Test Information
How will my item be delivered?

No, solar panels convert light into electricity. So as the light reduces in the day so does the output of the solar panel.

This depends on the load you have connected to the battery. You will need to calculate the watt-hour or amp-hours you are using in a period of time (see FAQ How to calculate your solar panel needs), then having a rough idea of the amount of direct sunlight your solar panel will receive each day. The solar panel needs to supply approximately 20% more than your needs to compensate for variables, such as cloudy days etc. Obviously the winter will have shorter sunlight hours per day than the summer, but you can work on an average of approximately 4 hours sunshine a day in the UK over a year.

Accessories what they do -

This device controls the charge to the battery. When the battery is fully charged the controller disconnects the solar panel from the battery.
All solar panels (except the 5w &10W) require a voltage regulator to ensure that the battery is not overcharged.

An inverter takes the DC (direct current) from the solar panel and creates a useable form of AC (Alternating current). Inverters are power hungry, so it is best to purchase (if possible) a product that operates on 12vdc.
Our inverters are High quality modified sinewave inverters to increase the output voltage from a 12v battery to 240v AC.
Useful Applications: Run Notebook computers, Radios, TV's, VCR's, Lamps, Fans, Fax, ETC

Failure of a solar panel is normally due to water damage to the panel itself or the connections. Also damage to the sealant around the frame could cause failure or mounting the panel incorrectly. If it is fixed horizontally it may be able to collect water and not a sufficient air gap beneath the panel can also cause damage.

Yes solar energy will work on an overcast day. Solar panels can produce electricity even when it is not placed in bright sunlight. This is because that although it might be a cloudy day there is always enough scattered light by which the panel will produce electricity. However, the production of electricity is not as high as when the panels are placed in bright sunlight.

Yes, solar panels work on light not heat, however the output will be less due to there being less sunlight hours due to the sun rising later and setting earlier than summer times.

Yes, solar panels will run equipment direct, these could be loads such as fans & pumps, but due to overcast days reducing the output, make sure the load of the equipment is not equal to the output of the solar panel. Panels will not run large appliances such as TV's or radio's without battery backup due to them requiring a more stable voltage.

You can clean the panel using a non-abrasive cleaner. Check battery connections periodically when you check battery levels. Fuse holders and connections should be kept dry and clean. In the long term check the sealing especially in marine use and reseal with a silicon sealant if damage is suspected.

The panels should preferably not be fixed horizontally as rain will collect in the frame and ensure that there is an air gap beneath the panel.
Make sure the panel is cleaned regularly otherwise output will be reduced.

You can use our wizard to do the calculations for you>>

Battery Ampere Hour:
The amp hour (ah) rating of a battery tells you how much amperage is available when discharged evenly over a period of time. The amp hour rating is cumulative, so in order to know how many constant amps the battery will output for a given period, you have to divide the amp hour rating by the amount of hours the load will be used.

Example:
If a battery has an amp hour rating of 85, and it will be used for 20 hours dividing 85 (ah rating of battery) by 20(hours of load) = 4.25. Such a battery can carry a 4.25 amp load for 20 hours before dropping to 10.5 volts. (10.5 volts is the fully discharged level, at which point the battery needs to be recharged.) Please be aware that it is not a good thing to discharge the battery fully. If the battery is fully discharged the solar panel may not be able to start the recharge, so add at least 15% more to you battery needs.

Please remember that these examples are for guidance only. The ratings of Solar panels are calculated in bright direct sunlight. Conditions such as indirect sunlight, cloudy, hazy conditions and partial shade will decrease the output. Also the length of daylight i.e.: summer vs. winter.

Calculating power using current and voltage
There are three ways of writing an equation for power, current and voltage:
Power = Current x Voltage so:
P = I x V
or
I = P divided by V
or
V = P divided by I

Where:

P = power in watts (W) P = power in milliwatts (mW)
V = voltage in volts (V) V = voltage in volts (V)
I = current in amps (A) I = current in milliamps (mA)

A milliwatt is a 1000th of 1 watt
A milliamp is a 1000th of 1 amp

Example: A 12 volt 15 watt solar panel in peak light conditions will give approximately the following current using one of the above equations. We have the 2 variables, volts and watts so the following equation can be used:

I = P divided by V

I = 15 divided by 12 =1.25 amps

So as the formula states that a 12 volt 15 watt solar panel in peak light conditions will supply a current of 1.25 amps.

Example:
If we say that a 12 volt 15 watt solar panel will supply 1amp-hour (average) for a period of 6 hours (in the summer) it will replenish the battery with 6amps in a day. If you have equipment which is connected to the battery that use more than 6amps per day then the solar panel you have may not be sufficient for your needs, as it will eventually drain your battery.
Please remember that these examples are for guidance only. The ratings of Solar panels are calculated in bright direct sunlight. Conditions such as indirect sunlight, cloudy, hazy conditions and partial shade will decrease the output. Also the length of daylight i.e.: summer vs. winter.

The following 240V appliances were tested using a 12v leisure battery and a Power Inverter High Quality 400-800 Watt to find out their approximate power consumption when using an inverter, as a guide for our customers when working out what solar panels and equipment to use:

• 240V Radio Cassette Player = 700mA
• 240V Home Computer (base unit) = 8 amps
• 240V Computer Monitor = 6 amps
• 240V Light Bulbs - for every 10 watts allow 800mA
• 240V Small Marshall practice amp & electric guitar = 900mA

We will be adding to this section as and when more appliances are tested.

Your item will be delivered either via royal mail guaranteed delivery or via our courier service nationally and either global priority or Royal mail international signed for internationally. However your item is dispatched you will need to sign for your delivery on arrival. Within the UK delivery is usually within 1-2 working days, internationally the delivery is usually within 5 days. All deliveries can be tracked and traced online and you will be emailed upon dispatched.

If you require any further help please do not hesitate to contact us at Contact@wavemaker.co.uk