Solar Harvester ltd

           Registered Office: - 61 Bridge Street, Kington, Herefordshire, HR5 3DJ

GoodWe Domestic DC Storage System with Pylon

This self-consumption package combines the GoodWe BP 2500 with a 2.4kWh Li-Lion battery from Pylontech.

The GoodWe BP series DC energy-storage system is compatible with most single phase on-grid inverters and therefore allows you to revisit most of your previous customers.

The Pylon batteries are modular. You can fit one and then add another at a later date if the energy needs on site change.

Retrofittable perfection

- Self-consumption

- Easy to add into Grid-tie installed solar system

- Internal DC switch

- RS232/Ethernet/Wi-Fi

- Comprehensive Growatt warranty program

Batteries Explained

 Batteries explained

SolaX Moixa Sonnen




                                       How do I choose the right battery size for my house?

The first step is to determine the amount of energy your solar panels produce per day.

To calculate this amount, you could either use a daily average or the amount of energy necessary to meet your needs during the winter peak, when you get the least sunlight. If you’re off-grid, your best bet is probably to use the energy you need to power your home during the winter peak.

If you choose to use your daily average, look over your past energy bills and add up your annual kilowatt-hour total. Divide this number by 365 to determine the number of kilowatt-hours you use per day.

If you’re in an off-grid location and don’t receive a home electric bill, you’ll need to calculate the kilowatt-hour usage of your home the long way.

This means tabulating the total wattage of each of your devices and appliances, then multiplying that number by the number of hours you use it per day. For instance, if you have 10 LED light bulbs, each of which is rated at eight watts, and you usually use each one six hours daily, you’ll need to develop a battery bank capable of sustaining at least 480 watt-hours (10 times eight times six) for lighting per day.

When using this wattage calculation method, create a digital spreadsheet to keep track of all your appliances, their wattage, and the number of hours you use each one.

After figuring out the watt-hour expenditures for everything in your house, add all the totals together to arrive at your home’s daily energy  total.

For instance,

if you have a TV that uses 100 watt-hours, a fan that requires 300 watt-hours, and a computer that uses 400 watt-hours, plus the 480 watt-hours of lighting mentioned above, your home’s total daily energy use would be 1,280 watt-hours (480 + 400 + 100 + 300) per day.

You can use the daily watt-hour total to determine the amount of power your battery bank needs to sustain your home for one day. Just divide your daily watt-hours by the voltage of your solar system.

For instance, if you’re developing a battery bank for the 1,280 watt-hour system described above and your solar system has a voltage of 24, you’d divide 1,280 by 24, yielding a quotient of 53.3 amp-hours. In other words, your battery bank needs at least 53.3 amp-hours of storage to provide power for one day.

You’ll also need to determine how deeply you expect to discharge your batteries. Totally discharging your batteries can shorten their life spans.

The recommended depth of discharge for lead-acid batteries is usually 25 to 50 percent. In other words, manufacturers recommend that you only use 75 to 50 percent of the battery’s total energy. Lithium ion batteries, on the other hand, can be discharged down to around 20 percent of their total storage capacity.

Since discharge rates require you to always leave at least some portion of the battery energy in reserve, you’ll need to upsize your battery bank by an appropriate amount to ensure you have enough usable energy.

For instance, suppose you need 100 amp -hours and your batteries can be discharged to a depth of 20 percent. In this case, you’ll divide 100 amp-hours by 0.8 (80 percent, or 100 percent minus your maximum discharge depth of 20 percent), leaving you with a final tally of 125 amp-hours.

Once you know how much battery energy you need to sustain your appliances and electronics each day, determine the amount of backup power you want. For instance, you could install a battery bank that would provide you with enough energy for one day (equal to your amp-hour total), half a day (by dividing your basic amp-hour total in half), two days (by doubling your basic amp-hour total), and so on.

Just remember: the larger your battery bank, the more expensive it will be, and the more space it will require.

Contact Us

Over the last year I have answered numerous phone calls

from existing customers who had been cold called by solar companies trying to sell them ad-on solar equipment.

Which quite honestly most are a waste of money, but lately

the phone calls have been asking about compliance IEC 62446

testing, and with this being a safety issue I spoke to several

other installers, which some say that they follow it, others don't. 

The essential need for all installers of PV systems in the UK

is to satisfy MCS requirements (for systems up to 50kW), as detailed in the DTI’s guide Photovoltaics in Buildings, this is fundamentally aligned to the BS EN 62446:2009 standard for

grid connected PV systems.

In short, this document sets out the minimum requirements for

PV system documentation, commissioning tests, and inspection

to ensure the safety and quality of system installation.

The standard includes specific measures to ensure that:

- The PV panels and electrical supply connections have

   been  wired up correctly
- That the electrical insulation is good
- The protective earth connection is as it should be
- There has been no damage to cables during installation

The standard describes various electrical tests to ensure that

the solar installation fully complies with MCS requirements.

While many of the more reputable and discerning solar PV installers recognise the importance of testing to the standard,

it is of serious concern that some installers are failing to perform the required tests, or at best only partly fulfilling this obligation.

Clearly where testing is not being carried out in accordance

with BS EN 62446, the system will be in breach of MCS requirements  and should not be eligible for feed in tariffs

or be connected to the grid.

This has potentially serious implications for the quality and

safety of the solar PV installations in question.

For example, it was recently reported that a house fire in

Kent was caused by a fault in a rooftop solar PV installation.

This mirrors the situation in the USA, France and Australia where property fires and surveys of solar PV installations

have raised specific concerns over incorrectly installed PV systems and their role as both a fire hazard and as a cause

of increased risk of electrocution.

All involved in the solar PV industry need to take responsibility

for the correct and proper installation of solar PV systems and

the recent MCS/Gemserv consultation on the competency of

solar PV installers seeks to address such concerns.

   However, the solution lies in ensuring compliance with all    relevant standards, including the solar PV testing and    documentation requirements of BS EN62446.

Only when this happens can the certification body be given the evidence that the work has been performed correctly and

the customer given the assurance that absolute best practice

has been followed in the installation and periodical testing of

their PV system.

It is now several years since we installed your system and

testing is now required