So What is a Hybrid Solar Solution?

Our Definition

 A Hybrid Solar System – also known as a photoVoltaic system – is defined as one which is used to supply green electricity to Home or Office (or any other Property such as a Boat or Mobile Home) some or most of the time without replacing the main supply (Grid)

Most commercial solar or photovoltaic solutions are designed to replace the entire electricity supplies for the Home or Business, and even to sell surplus electricity to the Grid. As a result, the equipment needed and the installation costs are very expensive, and it would take many years for the initial capital outlay to be recovered – a very costly way to “go green”.

Rising Prices and Power Cuts. With rising energy prices across the board in all areas, there are practical ways to reduce the increasing cost of electricity – and to be immune from Power Cuts – by Green Powering at least some of your critical day to day appliances independently from traditional electricity suppliers.

Main Advantages of Hybrid Solar Systems

  • Provides a free electricity supply to critical items in the Home or Office backed up by the main Grid
  • Low cost and can be scaled upwards according to the power output required
  • Simple and quck installation with minimal disruption – first step to Green Energy.
  • All necessary equipment (panels batteries etc.) are readily available from online stores
  • Can operate 24/7 with low power items such as surveillance equipment.

OBLIGATORY WARNING:   Equipment as described in this article  should be installed, adjusted, and serviced by qualified electrical maintenance personnel familiar with the construction and operation of the equipment and the hazards involved. Failure to observe this precaution could result in bodily injury.
The Author is a qualified electrician.

solar panel
An Array of 2 Solar Panels
solar batteries
Examples of Solar Batteries
Green Power Symbol
Green Power Symbol 2
Electrical Warning Notice

site practicalities

Any solar powered or potovoltaic solution will obviously need a high percentage of sunlight. Our direct experience of a Hybrid Solar system is in Crete, where the sun shines for 300 days in the year. The Solar Panels used - which are on a fixed mounting - need to be at the correct angle and to point in the right direction with an uninterrupted line of sight to capture maximum sunlight. When the weather is bad, the batteries are not being charged, and so power is being continuously drained.

The other main consideration is the distance from the solar panels to the batteries: this should be as short as possible to minimise power loss. And whereas the solar panels are exposed to the elements, the Batteries need to be kept dry and protected - indoors is a good option if possible.

How Much Power?

Now that the basics have been explained - i.e. how to get a solar or photovoltaic system to generate AC power from an Inverter - the next question is how much power can be provided? Or put more simply, which of the appliances in the property can be used with the new system? As one would expect, this depends on the number and power ratings of the Batteries in the system, and on the number and power ratings of the Solar Panels.
When the sun is shining, the Panels charge the batteries and any excess charge can be used to supplemement the battery output, but everything is controlled by the Controller (see above) which is often incorporated into newer more powerful Inverters.
The main purpose of the Solar Panels is to keep the batteries in as high a state of charge as possible.

Put simply, the more panels you have, the quicker the batteries in the system are charged. The more panels and batteries you have (total Power Output) the more electrical equipment can be operated and the longer the independent hyrbrid electricity supply will last.
When there are enough Batteries, kept at a sufficiently high level of charge, the electrical requirement of an entire property can be met 24/7.

Basic Equipment

Additional equipment needed - apart from the Solar Panels and Batteries - are a Charge Controller and one or more Inverters. The solar panels deliver electricty (DC - Direct Current) but this supply is variable - depending on factors such as the power of the sun, time of day etc.
The Charge Controller sits between the solar panel(s) and the batteries, and stops the electricity from the batteries going through the solar panels when there’s no sun and also optimizes the charging of the battery cycles by the solar panels.
Inverters convert the Direct Current from the Batteries to Alternating Current (AC) which can then be used to power most electrical appliances. They need to be closely situated to the batteries, and their power output rating is important. Modern Inverters have inbuilt charge controllers.

Batteries?

Batteries used in hybrid systems are not the same as the standard 12V battery used in cars. The types, and ultimate choice, of battery is outside the scope of this article, but there is a great deal of information on the Internet. Any battery model recommended by one of the major online stores like Amazon.de for use with a solar powered system should be fine. Battery life should be 5 years +

12V 24V or 48V System? Most batteries either come rated as 12V or 6V units. Connecting two or more batteries together in series is the way to increase the overall voltage of a system: many larger systems designed to provide electricity to an entire property are often rated as 24V or 48V rather than 12V mainly because the actual electrical current passing to the Inverter is significantly reduced.

A Hybrid system can either be rated at 12V 24V or 48V, and this rating will determine the rating of the requisite Charge Controller(s) and Inverter(s).
Batteries are heavy pieces of equipment, and some pre-planning needs to be made before any installation as to exactly where the Batteries will reside and how they will be kept dry and accessible for connectivity and for any required future maintenance or replacement.

Electrical Circuit Practicalities

Most existing properties will have an existing electrical circuit which is powered from the Grid – one of the National electricity suppliers. The existing Main Circuit often has built-in subsidiary circuits for appliances using different amounts of power – for example, a lighting circuit (rated at 5 Amps), a standard circuit (15 Amps), and a heavy duty circuit for things like cookers and airconditioning units (25 Amps +). All of these circuits have built in overload protection by way of circuit breakers and fuses, rated according to the maximum current envisaged.

When a Commercial PhotVoltaic solution is proposed, the main grid electricity supply is disconnected from the Property, and the existing circuits are then re-used by the new photovoltaic system.

With a Hybrid solution, the main house circuit can be used by the Solar/Photovoltaic supply. To do this, a special switch is needed which allows the Homeowner to select Solar Power or Mains Power as required. Both Power sources need to be isolated from each other for very good reasons, including safety and simplicity.

Alternatively, for small systems where only specific items need to be powered, a separately wired circuit can be used.

New and Independent Electrical Circuit - No More Power Cut Worries

Installing new circuits to a Home or Property may be required for a Hybrid Photo Voltaic Solution.

However this is not a difficult or expensive process, and just requires some additional wiring with appropriate power outlets to the rooms or areas which have the equipment that needs the independent power supply.

So What Configuration is Recommended for a Hybrid System?

Based upon the Author’s own experience in Crete, we would recommend a 12V Hybrid System with

  • a minimum of 3 x 100 Watt Solar Panels, (or one 300 W Panel)
  • 2 x 12V Solar Batteries – minimum 100 Ampere Hours each.
  • 20 AMP Charge Controller
  • 2kW Inverter

This system will produce enough daylight power to run a normal Fridge, TVs, Computers, Laptops, Routers. Office Equipment, Lighting, Cooling Fans, most Kitchen Appliances (including Microwaves rated up to 1kW), the Pump for a basic Central Heating System and other Power Tools. By adding two more 12V x 100 Ah batteries to the system, (total 4) night-time power to the same equipment could also be produced. 

Total Estimated Cost of Equipment approx £1000

To support more highly power rated appliances such as larger Microwaves, Main Ovens, Air Conditioning Units, Compressors, electric heaters etc. a larger 24V system would be recommended.

Global Solar Map, FAQs and Contact Us

Note from the Author. I live in Crete in the Apokoronas Area, where we have sunlight for 300 days in the year: clicking on the link will take you to a global solar map where you can find your exact location for solar information.
The system I describe I installed 5 years ago – still going strong. If you live near me, I can make a trip to carry out an intial survey and personally plan the project.  If you require further information, please use our Contact Form.

Frequently asked questions

The advice on the equipment needed is good for any Hybrid Photovoltaic System. The only difference would be to the Voltage Rating required. For example, most electrical supplies in Europe are rated at 220 230V, and the UK at 240V. The USA has 110-120V as the standard, so you would need to take this into account when building your system, otherwise your electrical  appliances will not work! I will respond to any general questions that are raised in our Contact Form.

You will need the services of a local electrician if you are not confident, or not willing to do the work necessary. However, with the Hybrid solution, the electrical work required is not difficult and so should be reasonably inexpensive.

Yes asolutely! As long as your property is reasonably close to me in Crete (Apokoronas area) I will organise a “site survey” with you so I can check that Panels can be installed in the right area, and discuss where the equipment will go, and whether you can use your existing Home Electrical Circuit or which rooms will need additional wiring etc. To get started, just fill in the Contact Form including your phone number and address, and I will telephone you or email within 48 hours.  I may also be able to provide the services of a local electrician to complete the system for you, if you do not have a suitable contact. There will be a Project Management Fee which we can discuss further once we have your form and contact details.

The advantage of the Hybrid solution is that you can always fall back on the normal electricity supply until the Batteries are back to operating charge levels. One way of recharging the batteries at night or in poor weather (i.e. no sunlight) is to use a standard 12V charger – either powered through the Mains supply, or as in my case, by a small 1.4 Kw petrol driven Generator (which I also use to power appliances on the Hybrid circuit if necessary).

A Hybrid system like this can easily support the low power requirement of surveillance cameras 24/7. I installed a surveillance system in my property using 3 video cameras (cost approx £500) and can monitor the property 24/7 from anywhere – the UK for example –  using the app that comes with the equipment. As regards security lighting, inside lights can be set via a timer to come on at various intervals. For outside the property we would recommend “stand-alone” solar powered security lights; these can be wall-mounted and set for motion detection.

All the equipment for a Hybrid Solar Solution will be bought by the owner of the system. Whether this is bought from an on-line store or local supplier, the normal equipment Warranties and Guarantees will apply. In reality, there is not too much that can go wrong providing that you stick to well known brand names. We can advise you on the brands that we would recommend. 

Apart from the main equipment needed, which is listed in the Article, other costs would include wiring and adapters as required, trunking and power points for any independent circuit and the associated labour costs associated with connecting and installing the system. In my case, I fixed the solar panels to a timbered flat roof using a wooden frame tilted at an appropriate angle. Where a concreted flat surface is available, a strong metal panel mounting frame structure like the example shown at the bottom of this page would normally be recommended, with possibly some form of tilting mechanism to optimise the angle of the panels to the sun as seasons change and the sun’s position changes.

If a site survey is possible, we would definitely recommend it. There would be no point in proceeding if the property is not suited for one reason or another, and a plan is always a good idea before any project gets under way. One of the key considerations is how much power can be generated per solar panel, and this directly affects how many panels you need. Assuming that the panels will be mounted on a roof or other flat area, the angle of the panels relative to the sun’s actual position over the course of the year is critical for optimal power output, as is the structure that will support the solar panels.  A basic site survey would cost from £100, and includes all practical advice on equipment positioning and additional wiring that will be required .

Assuming that the equipment has been received, and a local electrician/installer is available, the system can be up and running within a couple of days.

The other common source of Green Energy is from a Wind Turbine, and so if you live in a property with medium to strong winds, this could be an additional source of power. Wind generators are going to be constantly generating power, which means you have to have somewhere to dump the excess energy that is produced. There are Charge Controllers that can handle both wind and solar panel outputs and which are made specifically for this purpose, so you should purchase one of these devices if you are trying to utilize a wind generator. This will allow you to channel the excess energy that is produced by the wind turbine system into a water heater or another appliance. Using one of these controllers takes a potential problem and creates even more efficiency, as the excess energy can always be used. However, we have no personal experience of Wind Generators/Turbines, and there are practical problems to overcome – such as noise, the size of turbine required to produce any meaningful power, and its physical location. 

The first step would be to work out your average monthly electricity consumption (how many kWatt Hours) which you would be able to check from your Electricity Bill. To be more accurate still, it would be worth checking the Bill for each month of the year – for example, bills may be higher in the summer when air conditioning is used – and so the highest monthly reading would be your target figure for Solar Power. Once the target is known, it is fairly straightforward to determine the number of Solar Panels required, and Batteries to cover night-time electricity, and a system can be built to supply that Power. Most properties (homes) would consume in the order of 10kWhours per day using all electrical appliances without restriction. A typical system is shown here, where a total of 20 solar panels are used producing over 9kW of power and at a cost of under US$10,000.

For a Home, there are normally two options for mounting a solar panel array. The first option is on a south facing roof of the Home, but this will depend on the slope and type of the roof, and may be inappropriate or difficult to achieve.

The second option is to mount the array on a flat surface, such as a terrace, where the frame structure can be securely fixed to a base. Where  Panels are fixed outdoors, they need to be 100% weather proof, and secured well enough to withstand any strong wind. An example of a solar panel mounting structure is shown here.

Another option is to consider “portable” solar panels which can be quickly set up on a suitable terrace, but obviously a close eye needs to be kept on the weather conditions!

In principle, yes, possibly by using a power selector switch an example of which is shown on this page. However, this does depend on the size and power of your solar hybrid system. Providing there is sufficient power available, there are some considerations to be made – which may require high power consumption items – such as air conditioning units and cookers – to be physically disconnected on your circuit panel prior to switch over. These appliances should be separately wired to the higher rated sub-circuits – 25A plus – so it would be merely a case of switching off that particular sub-circuit before selecting the Hybrid Solar Power input.

Of course, if your PV system is sufficiently rated, you can use all your existing home circuits

The Power Selector Switch shown is an internal wall mounted item, which would either be situated close to the Home Circuit Panel or – if a weather resistant Switch is chosen – this could be mounted externally close to the main electrical meter. This would require a qualified electrician to instal it. 

The simple answer is Yes, providing the solar power output is sufficient – which means at least a 5 kWh system. EVs can be charged directly from a house circuit. Some properties now have car ports, where the cars are parked under a flat roof with solar panels providing EV charging directly to the vehicle. If the roof structure supports enough panels, the power output can also be used for home use – a practical solution if you have the space available (and any required planning permission).

Summary
How to Build a Simple Solar Powered system. Crete Greece
Article Name
How to Build a Simple Solar Powered system. Crete Greece
Description
Practical advice for building a Hybrid Solar System in Crete Greece. Interested in going "green" or in reducing your energy bills? Need a backup electricity supply? How to be energy independent.
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Power Comms
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