Do solar powered gates work ?

Ours do and here is why

With anything powered by solar panels it is all about power consumption. Not just the power used to open and close the gate or barrier but also the power used when the control unit is sitting there listening out for a signal to open.

Here at Dofygate we took that as the number one priority.

• Low stand by current – not a single electrical component is on that does not need to be on. Not even an LED. Accessories such as a keypad or sensors are activated only for the time they are used. Our stand by current consumption is 4.2 milliamps

• Low operating power consumption – why lift a long heavy barrier when you can lift a strong light one half the length ? The Dofygate arm is carbon fibre and folds in half lowering the centre of gravity the motor has to lift and limiting the momentum that needs to be controlled.

The Maths

The battery we supply is a 7amp hour 12v sealed lead acid AGM battery providing 5000 milliamp hours (ma/hrs) of useable power.

Assuming 20 open/shut cycles per day 7 days a week.

Power out

The gate uses 1500 ma average to open in 3.5 seconds and the same to close

Standby current use                24*4.2=101ma/hrs

Operating current use             20*1500*7/60/60=58ma/hrs (2.9ma/hrs/lift)

Battery useable power            5000ma/hrs

Total daily consumptions        159ma/hrs

Backup held in battery            31 days

Total power use in a week      1113ma/hrs

Power In

The panel generates 280ma on a sunny day every hour and only 15-20ma/hr on a dull day. Winter matters – summer provides more power than needed.

The winter day length is 6 hours and a sunny day may only have 2 hours of sunshine

So looking at 1 week in the winter

1 Sunny day solar power         2*280=560ma/hrs

Remainder of that day            4*30  =120ma/hrs

6 days of dull weather            15*36=540ma/hrs

Total power generated           1160ma/hrs

In the summer days are longer and sunny days more likely so the panel will produce much more than needed. Solar battery charging is controlled to prevent overcharging the battery.

Our solar powered gate does work and it works because we have controlled power consumption.           It matches the above calculation and to cross reference will open and shut over 1700 times in practice on a battery with no charge going in. This matches the theoretical calculation

Battery capacity (5000ma/hrs)/ power used per lift cycle (2.9ma/hrs) = number of lift cycles in the battery (1724)