ᐅ Pellets combined with solar thermal or photovoltaic systems?
Created on: 15 Jan 2020 09:02
Z
Zigenpeter86
Hello everyone,
I am currently facing a small issue with planning the heating system.
A pellet stove with about 12 kW output is firmly planned. However, it should be supported by solar energy.
The question now is which option makes more sense...
1. Support from solar thermal system
2. Photovoltaics with an electric immersion heater in the buffer tank
Details:
Floor area about 175 sqm (1887 sq ft)
Building style: urban villa with basement
KfW 55 standard
Ventilation with heat recovery
Underfloor heating throughout the house
Orientation: south (10 m (33 ft) roof width facing south)
Roof pitch about 23°
The question is also which combination is best for subsidies/grants.
Thank you very much
I am currently facing a small issue with planning the heating system.
A pellet stove with about 12 kW output is firmly planned. However, it should be supported by solar energy.
The question now is which option makes more sense...
1. Support from solar thermal system
2. Photovoltaics with an electric immersion heater in the buffer tank
Details:
Floor area about 175 sqm (1887 sq ft)
Building style: urban villa with basement
KfW 55 standard
Ventilation with heat recovery
Underfloor heating throughout the house
Orientation: south (10 m (33 ft) roof width facing south)
Roof pitch about 23°
The question is also which combination is best for subsidies/grants.
Thank you very much
B
boxandroof15 Jan 2020 11:39For me, no storage. 10 kWp. The heat pump modulates between 300 and 1000 watts. Usually max 600 watts for hot water. In summer, I always have at least 500 watts, usually more, except during thunderstorms.
But hot water production is not the major cost factor, and also the reason why solar thermal systems are not cost-effective. I would focus on the heating.
But hot water production is not the major cost factor, and also the reason why solar thermal systems are not cost-effective. I would focus on the heating.
N
nordanney15 Jan 2020 11:39Zigenpeter86 schrieb:
Air-to-water heat pump .... is such a heating system so much cheaper to purchase than a pellet heating system.If you take into account the necessary basement space – YES. But since you are building the basement anyway and are willing to spend 20 m² (215 sq ft) x 2,000 € just like that, the price advantage naturally decreases (comparison of two systems with equal capacity – although you will definitely need a significantly smaller heat pump).Viessmann Vitoligno 300-C pellet boiler, 12 kW, – approximately 12,000 € according to online sources
Viessmann Vitocal 200-S air-to-water heat pump, 12.6 kW, – approximately 7,500 € according to online sources
In addition, there is the chimney, no idea what that costs (around 2,000–3,000 €?) plus the annual chimney sweep fee.
Let’s just say the heating system with everything costs 7,500 € less than the air-to-water heat pump. At 30 cents per kWh electricity cost, that corresponds to 25,000 kWh of electricity you could buy. That should cover the entire heating costs for 10 years – just from the savings on the initial investment.
Z
Zigenpeter8615 Jan 2020 11:56@nordanney
Why should a pellet heating system require 20 m² (215 sq ft) more space? If it’s a heat pump, then it’s always without an outdoor unit. I don’t want such a device standing in the garden.
But the calculation is interesting. I need to work that out in more detail, especially regarding the consumption for domestic hot water.
As I said, a chimney will be installed anyway because of the fireplace in the living room.
Why should a pellet heating system require 20 m² (215 sq ft) more space? If it’s a heat pump, then it’s always without an outdoor unit. I don’t want such a device standing in the garden.
But the calculation is interesting. I need to work that out in more detail, especially regarding the consumption for domestic hot water.
As I said, a chimney will be installed anyway because of the fireplace in the living room.
N
nordanney15 Jan 2020 12:14Zigenpeter86 schrieb:
Why should a pellet heating system require 20 sqm more space? No idea. Just an estimate based on pellet storage space, equipment size, auger feed, etc.
Zigenpeter86 schrieb:
If it’s a heat pump, then always without an outdoor unit. I don’t want one of those outside in the garden. Here we go again with the prejudices.
Just place the outdoor unit on the garage or hide it behind plants. I have 7,500 reasons in my calculation for that...
Zigenpeter86 schrieb:
But the calculation is interesting. I need to take a closer look at it. Also regarding domestic hot water consumption. Domestic hot water is already included with the air-to-water heat pump. Of course, all just rough and approximate calculations.
Zigenpeter86 schrieb:
As I said, a chimney will be installed anyway because of the fireplace in the living room. Then the advantage is obviously smaller, as you only need the additional part in the basement.
If you are only looking at the costs, you won’t avoid an air-to-water heat pump. Have a look at the heat pump consumption database [de]. There you can see real consumption figures and realize that they are not power guzzlers.
You can always run the numbers in many ways. You need to come up with a concept that fits the house, the surroundings, any available subsidies, and your personal preferences.
I can also do the math now: air-to-water heat pump + photovoltaic system + heating surfaces cost me about 20,000–22,000 euros with self-installed work. This gives me heating and electricity costs of around 50€ per year.
My parents have a pellet heating system. I think 20 sqm (215 sq ft) is not enough; the unit is huge and occupies an entire large basement room.
I can also do the math now: air-to-water heat pump + photovoltaic system + heating surfaces cost me about 20,000–22,000 euros with self-installed work. This gives me heating and electricity costs of around 50€ per year.
Zigenpeter86 schrieb:
@nordanney
Why should a pellet heating system require 20 sqm (215 sq ft) more space?
My parents have a pellet heating system. I think 20 sqm (215 sq ft) is not enough; the unit is huge and occupies an entire large basement room.
Z
Zigenpeter8615 Jan 2020 12:31The garage area is not ideal for the heat pump (hip roof). Of course, you can hide it somewhere, and they’re not that loud anymore, that’s true. Still, there’s just a bad feeling about the heat pump. But I will take a closer look at the actual energy consumption of such a unit.
I was thinking about an additional 20 sqm (215 sq ft) compared to a heat pump. The bunker is about 2 by 3 meters (6.5 by 9.8 feet), and the heating unit itself is 1.5 meters by 1 meter (5 by 3.3 feet), so not that much space.
It also depends on the size of the bunker and the burner.
I was thinking about an additional 20 sqm (215 sq ft) compared to a heat pump. The bunker is about 2 by 3 meters (6.5 by 9.8 feet), and the heating unit itself is 1.5 meters by 1 meter (5 by 3.3 feet), so not that much space.
It also depends on the size of the bunker and the burner.
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