The largest solar electricity system in the region has been installed at Kimi Ora Eco Resort in Kaiteriteri.

A north-facing hillside behind the resort is covered with 256 square metres of solar panels, which are expected to produce 59,000 kilowatt-hours per year, enough to power eight average homes.

Resort manager Aaron Dunbar said that because the majority of the power produced would be consumed on-site, the savings should mount up quickly.

The $110,000 40-kilowatt system is expected to pay for itself in savings in 6.4 years.

The grid-tied system can feed back to the national power grid but most of the power it produces will be sucked up by the demands of the busy 23-unit resort.

"That's where the savings are because the power company only gives you half of what they charge you," said Dunbar.

He said the resort's winter power bills averaged about $5000 and in summer were about $3000.

The system had long been a dream of Kimi Ora's owner, Dietmar Glaser, who is Dunbar's father-in-law.

"He's always been far ahead of others in his ideas and he loves this sort of stuff. It also fits the image of the eco-resort," said Dunbar.

Glaser spent a month clearing the steep hillside of gorse and scrub and then Kimi Ora staff built the timber frames that the panels are mounted on.

The solar system & installation was provided by Nelson company, Current Generation.

Current Generation installation foreman Shane Naughton said because of worldwide demand bringing down the cost of solar panels, the cost of solar installations was about a third of what it was five years ago.

Company owner Arny Ahnfeldt said he had seen a lot more interest in solar over the past three years and that a average 3 kw system cost about $10,000 fully installed, which would provide about half the power for an average home, it was still a "significant investment".

He believed the 40-kilowatt system was the largest in Nelson/Tasman and one of the largest in the country. A 17-kilowatt system in Collingwood was probably the area's next largest.​

BASICS
​Solar power is the technology of harnessing usable energy from the sun. Solar panels are made up of photovoltaic (PV) cells. A module is a group of cells electrically connected and packaged in one frame. PV cells are composed of special materials called semiconductors, most commonly silicon. When energy in the form of heat from the sun is added to the silicon, it causes electrons to break free from their orbit around the nuclei of the silicon atoms. These atoms are left with a positive charge, while the electrons carry a negative charge. The electrons, or free carriers, carry an electrical current. The free carriers roam around until they find atoms lacking an electron and then fall into the orbit of these atoms. The electric field surrounding the solar cells acts as a diode allowing electrons to flow in a certain direction. This flow is an electrical current. When using metal on the top and bottom of the cells, we can direct that current to be usable outside of the panel.

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ENERGY STORAGE
 
A solar power system requires an energy storage unit called a battery in order to use the energy obtained throughout the day. 
The use of batteries requires a charge controller. The charge controller ensures that the batteries are not overcharged during the day or drained too much at night. Once the battery has been drained down to a certain level, the controller will not allow more current to be drained in order to protect the battery from damage.

We want to let you know how investing in a solar power system can give amazing returns on your money

As the price of grid connected solar power systems has decreased dramatically over the last few years, investing in a system now produces a high return on investment (ROI) making it far more attractive than putting your money in bank term deposits or similar investments. 


The size of the solar system that you install will determine your ROI, which will generally range between 7% and 12%.

Choosing a solar power system for your home is a big decision. That’s why we tailor a system that suits your requirements.

We pride ourselves on our workmanship and attention to detail.

A solar power system uses photovoltaic (PV) technology to harness the sun's rays, converting sunlight photon energy into electrical current.
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Solar power panels produce energy from daylight, not direct sunlight, so they still produce electricity on cloudy or overcast days.

Solar power can be used directly in your home to power lights and appliances – or exported to the electricity grid.

At night when your panels can’t produce electricity, you draw your electricity from the electricity network in the normal way.

A solar power system contains two major elements: solar panels, which are usually mounted on a rooftop, and an inverter.

The solar panels contain two layers of silicon, one with a positive charge and one with a negative charge. When the sun's rays land on a panel, electrons move from one layer to another, creating an electrical current. The inverter takes the current and converts in into usable power (240V AC).

Solar power is very safe, reliable and effective, requiring no moving parts, it emits no carbon dioxide, fumes or pollution, and the panels will typically produce power for at least 25-30 years.

Grid Tie Solar is an alternative power system designed for homes and commercial buildings where they are connected to the electricity company (or grid).

The system provides a way for you to produce your own power and thereby reduce your electricity bill, any excess power that is made can be fed back into the mains grid electricity provider.
 
This means that when the system is generating more electricity than is needed, for example, during the day when no one is home, you could be paid for the surplus.
 
Each electricity retailer has their own terms and conditions for buying excess electricity. The price that they offer per kilowatt hour (kWh), called the ‘buy-back' price, will also vary.
These systems are called ‘grid-connected', ‘grid-tied', or ‘grid-interactive'.

V Magazine
December 8 2017

BYD has now launched a battery storage system that advances progress in three categories: modularity, charging and discharging capacity, and efficiency. With regard to efficiency, the company also creates transparency, and has submitted its technology to pv magazine’s storage system comparison. The judges therefore decided to select BYD for the pv magazine award in the category of top innovation.

To increase efficiency, BYD has given the new battery a high output voltage. There are real and fake high voltage batteries of this type. The fake ones use a transformer or a step-up converter to produce the high voltage. This in itself brings little or no increase in efficiency. The BYD system is one of the real ones: The company connects the batteries in series, so that the output voltage increases with each module. The variant with a storage capacity of 10 kWh delivers more than 400 V. The high voltage of the BYD battery makes it possible to dispense with the transformer in the battery inverter. This in theory increases efficiency. And measurements show that the concept also works in practice, although with a system performance index of 89.0%, the gap between it and the previously tested low voltage systems is not huge. A discussion about this shows the parameters and applications that determine whether high voltage will be able to deliver its full potential in the future.

Apart from the Chinese manufacturer, only Sony currently has a “real” high voltage battery on the market. One reason for this could be that the insulation requirements increase, and manufacturers therefore refrain from using high voltage systems.

A major step in the new BYD product is its charging and discharging performance. The battery can be fully charged or discharged within an hour. ­Technicians say it has a C-rate of one. The battery with a capacity of 10 kWh can therefore be operated with a capacity of 10 kW. For five minutes, it can even deliver twice that output. In the home sector, C-rates of only a quarter to three quarters are common.

High C-rates can be relevant when peak loads occur in off-grid systems where the network is not available as a safety feature. This is also the case in business models in which peak loads are capped in commercial operations, where the battery is supposed to generate additional income through the marketing of primary control power, or where it serves as an emergency power supply. In a private home, it is conceivable that the battery could be used to quickly charge an electric car with the stored solar power. However, all of these applications require the proper power electronics.

Currently, BYD batteries can be used with the SMA Sunny Boy Storage, Victron Energy, Goodwe  which is designed for low power home applications. BYD is working to form partnerships with other manufacturers for other applications. Soon BYD and the inverter manufacturer Kostal will release a solution.
What catches the eye in a first look at the system is its modular design. The batteries are stacked on the floor. A plug system connects them and no wiring is required. But the details go even further. Since each module has its own battery management system, modules of differing ages can also be combined with each other, even though the capacity of the new modules used in the series configuration could be slightly reduced. This facilitates replacement and expansion after a few years. Since a module has a capacity of just 1.28 kWh, the capacity can be finely graduated to suit the application. Several towers can be connected in parallel to provide a total of up to 57 kWh. As a result, the system is also suitable for applications in commercial companies.

PV MAGAZINE AWARD
Prize for good ideas: 
BYD: High voltage battery
“High voltage” is one of the keywords with which BYD brings another variant of its batteries to the market. The technology promises better efficiency and the company creates transparency by having the system measured and publishing the results. On top of that, it is involved in the further development of storage systems. The new product also allows high charging and discharging performance, which is important for some applications, and has high modularity. , the new BYD product is worthy of the pv magazine award in the “top innovation” category, according to the jury.

​The BYD B-Box can help households and businesses to slash their electricity bills by storing the output of their rooftop solar panel systems for use in the evening, when household electric appliance demand tends to rise. The B-Box can minimize the amount of solar energy that is fed back to the grid, as well as the impact of costly electricity tariffs.“The B-Box series offers a wide range of renewable power capabilities to meet light to heavy electrical load usage, off-grid or on-grid, single-phase or three-phase applications.” said Julia Chen, Global sales director, BYD Batteries. “Ideally, the B-Box can be integrated to a fully sustainable energy-independent enterprise or lifestyle, enabling its users to reduce reliance on electricity from fossil fuels.
​
BYD is the world’s largest manufacturer of rechargeable batteries

Those three letters stand for Build Your Dreams and apparently their dream was to build a battery box and sell it for storage in grid-tie solar systems because that’s exactly what they’re doing with their B-box battery systems.
There are 2 product lines – the High Voltage1 (HV) and Low Voltage (LV) B-Boxes, each in a variety of storage capacities.
The one most likely to be used for home energy storage is the B-Box LV Residential, which comes in 4 sizes.  The smallest being the B-Box 2.5 with 2.45 kilowatt-hours of usable storage and the biggest, the B-Box 10 with 9.8 usable kilowatt-hours.
The B-Box batteries pack more power per kilowatt-hour of storage than almost any other system.  BYD batteries are lithium iron phosphate, which is the safest lithium chemistry. 

BYD has confirmed a retail price for the B-Box 10 - $9,950 including GST

BATTERY BACKUP SYSTEMS
ADD VALUE TO YOUR GRID-TIE SYSTEM

​A battery back-up system adds two levels of functionality to a grid-tie solar system:
A battery back-up system from Current Generation will charge during the day and then release the stored energy overnight, with no disruption of power supply to the home. Energy will only be ‘imported’ from the national grid if it is necessary, and less energy imported from the grid means a lower power bill. This also protects the consumer from rising electricity prices.
· In the event of a power cut, the solar array will continue to work without any disruption of power supply to the home. As long as the batteries are being sufficiently topped up each day with solar energy, the power cut will not affect the home.
 
ANY HOME CAN BENEFIT
Battery back-up systems are ideal for adding value to a grid-tie power system (solar, wind or hydro power), however they can also be used in a normal home or business without a renewable energy system for emergency back-up, and/or to maximise benefits from off-peak electricity rates.

If you are considering adding batteries to a new or existing solar power system, but don't know where to start, you've come to the right place.
Batteries are becoming more cost-effective over time, and in 2018 energy storage can make financial sense for some solar owners.
As energy storage is a big investment, ensure you understand the basics before parting with your cash.

How does solar battery storage work?
A simple grid connected solar system does not need batteries to function.

If you think about it - it actually uses the grid as an infinitely large battery. If the solar panels on your roof are creating more power than is needed by your home, then the excess goes into the grid. Later, if your panels can't produce enough electricity, electricity is drawn from the grid to make up the difference.

There are two reasons you may want to add batteries to a grid connected solar system:

1. You want to store excess solar energy generated by day - and use it when the sun isn't shining.
2. You want to have backup power available if the grid goes down.

Many old-school installers (and most of the lumbering old utilities who haven't caught on yet) believe that Option 1 (batteries for nighttime use) and Option 2 (batteries for backup) are inseparable, and that all solar battery storage systems must offer both.
However, since Tesla's Powerwall came on the scene smart installers have realised that it can make sense to offer a solar battery storage system that does not offer any backup function.
Why? Because it makes the system a lot cheaper. If you are wondering whether you need backup power, this article may help you decide - but really, if you live in any major town or city, when was the last time you had a blackout at all, let alone one that lasted more than a few hours? 
The rest of this article will give a brief overview of how each type of solar PV system works, for those who are curious (or just want to know why options 1 and 2 are vastly different in complexity and price).

Let's get started!