RSS Feed

SunMachine – Heat to Electricity machine.

Posted on

Micro CHP furnaces produce both heat and electricity. (Original article; From John Robb;

NOTE:   CHPs work on the simple principle that 80% of the energy the power company uses to produce electricity is usually lost as heat.  So, if you produce this electricity where you use it, it’s possible to use heat that would otherwise be lost, to heat your home and your hot water.

Here’s how it would work.  I would install a micro CHP like a furnace.  Like any furnace or pellet stove, it would turn on whenever I needed heat.  The only difference would be that it would also generate electricity when it does turn on.  The first 20% of the energy produced to heat my house would be used to produce electricity instead.

In concept, this would be a pretty amazing system.  The costs of fueling the system with pellets would be largely offset by electricity it produces.

Unfortunately, there isn’t a MCHP out there that burns wood pellets yet.  There was one, from a German start-up called SunMachine (it used a Stirling engine).

German start-up called SunMachine (it used a Stirling engine).


Tech specs for the SunMachine CHP, here they are:

Datasheet Sunmachine-Pellet
1.0 CHP unit
Electric power fed to grid: —- approx. 3 kW (electric output)
Thermal power: approx. —– 10.5 kW (thermal output)
Efficiency (electric): ——– approx. 20 %
Overall efficiency: ——— approx. 90 %
CHP coefficient: ———– 0.286
Flow temperature: ——— 50 – max.75° C / 122 – max.162° F
Return temperature, max. — 60° C / 140° F
optimal return temperature: — 30° C / 86° F
Sound emission: ———- approx. 49 dB
Color: —————– RAL 5001 (blue-green)
Weight: (without covering): — approx. 410 kg / approx. 903.89 lbs
Dimensions LxWxH in mm / inch: 1160x760x1590 / 45.7?x30?x62.6?
1.1 Burner unit
Fuel: woodpellets, DIN plus (german industrial standard)
Power: 14.9 kW fuel provided
Maintenance interval: recommended once a year or every 3,500 operating hours
1.2 Stirling engine
Cylinders: 1
Cylinder capacity: 520 ccm / 31.73 cubic inch
Speed range: 500 – 1,000 rpm
Working gas: nitrogen
Working pressure: max. 40 bar / max. 580 PSI
2.0 Input with inverter
Feed to grid: single phase 230 Volt 50 Hz
Grid control: 3 phases through build-in grid disconnecting device
2.1 Inverter
Nominal output: 3.4 kW
Peak capacity: 3.8 kW
Input voltage: 350 – 750 Volt
Efficiency: max. 95.7 %
Power factor cosPhi: 0.997
3.0 Control Unit
Interface: graphic touchscreen display
Interface RS 232: suitable for modem and PC (readout of important data)
Optional: 3 heating circuits and one warm water controllable,
switching output for peak load demand
4.0 Feed
Pellet-supply-container: approx. 50 l / approx. 13.2 US gallons
Pellet feed from storage room / bag – silo / via vacuum delivery with internal day / night control
subterranean tank to sunmachine: (closed system)
5.0 Exhaust
Exhaust: Exhaust gas routing after request with solid fuel boilers condensate
6.0 Recommended heat-store stratified storage: min. 1,000 liters / 264 US gallons incl. heating rod 9 kW

It didn’t last long.  SunMachine never made it out of the start-up phase.  It went bankrupt a couple of years ago before it was able to ship product.


About pfiddle

Fiddle teacher - mostly Irish trad. Fiddle, mandolin and concertina. Eco-warrior, won E.U. Green Flower Award for Eco Accommodation. Also Irish (Gold) GHA. Green Hospitality Award. Mad keen on self-build - especially straw-bale and cob. 55 with a full head of (slightly) graying hair. No tattoos or piercings. Fond of animals - but legally so. Fond of food - I eat nothing else. Vegetarian by choice, Irish by the grace of birth, Munster by force of (rugby) arms.

One response »

Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )


Connecting to %s

%d bloggers like this: