Wood Pellet Bags vs Bulk
Pellets may be purchased in bulk or in bags. As a result there are several different storage configurations a wood pellet heating system can use.
Bags are usually about 15kg in weight and may be purchased in any quantity. Larger quantities of bags may be delivered on a pallet. A pallet usually contains about 1 tonne of pellets.
- Easy to handle for small amounts of pellets
- Pellets remain protected against moisture during storage
- Can be stored in any indoor location
- More handling needed for larger volumes
- More Expensive than bulk pellets.
- No SEI grant available.
Wood Pellet Delivery Truck
Bulk deliveries are made by truck. The minimum bulk delivery is usually 3 tonnes. Pellets delivered in bulk are usually about 30% cheaper per kg than bags. Bags are convenient when smaller amounts of pellets are used but bulk deliveries are better for larger quantities.
- Easier to handle for larger volumes
- Typically 30% less expensive than pellets purchased in bags
- SEI grant available for existing houses as long as you use bulk storage
- Special pellet store needed meeting the specifications of the pellet supplier. This can be both large and expensive.
- Minimum deliveries are normally about 3 tonnes.
Choosing what's right for you
There are several possible configurations of a pellet heating system. You need to choose the option that gives you the best mix of value for money, comfort and automation.
1. Store indoors on pallet or elsewhere. Load the hopper manually as required
In this situation the user purchases pellets in bags. These bags are usually 15kg. A small hopper is attached to the side of the boiler which can hold 100-300 litres of storage. The user will fill up this hopper soon before it runs out.
- Pros: The cheapest installation possible. Very reliable with little moving parts.
- Cons: Higher pellet costs when purchased in bags. More work for the user. Not grant aided.
2. Use a suitable vessel to manually transfer the pellets from the store and load into the hopper
In this situation the user will install a bulk pellet store that can hold 3-4 tonnes. When the 100 litre hopper attached to the boiler begins to run out, the user takes pellets from the bulk store using a bucket or other vessel and loads them into the 100 litre store.
- Pros: Still a relatively cheap installation. Cheaper pellet costs when purchased in bulk. Grant aided.
- Cons: More work for the user
3. Do not use a boiler hopper and directly feed the boiler with auger from the store
In this situation, the user installs a bulk store directly beside the boiler and connects it directly using an auger. This means there is no need for the 100 litre store.
- Pros: Cheaper pellet costs when purchased in bulk. Grant aided. Fully automatic.
- Cons: Requires a lot of space in the boiler room.
4. Install an auger or vacuum transfer system to move the pellets from the store to the boiler hopper
In this situation the user installs a bulk store but does not have it beside the boiler. An auger or vacuum transfer system moves the pellets automatically to the 100 litre store attached to the boiler.
- Pros: Cheaper pellet costs when purchased in bulk. Grant aided. Fully automatic. Does not take a lot of space in the boiler room.
- Cons: The dearest installation. Least reliable option (a lot of moving parts)
It is up to the user to decide which type of system is right for them. For more information on bulk stores and augers, please keep reading.
Read on about bulk storage here: Homeowners:Wood_Pellet_Bulk_Storage_and_Augers